in this invention , dna tags are first constructed based on dna and forms dna tags . then said every single dna tag is amplified by single molecule amplification . sequencing of dna tags is conducted by using sequencing anchor with at least one degenerate base . sequencing signal is produced along the sequencing process . then sequencing signal is collected and processed to call sequences of dna tag . in this invention , since dna tags are sequenced by using sequencing anchor with at least one degenerate base , length of dna tags that can be directly sequenced is extended . both short and long dna tags can be sequenced . thus application of dna sequencing is expanded . fig2 shows a process of dna sequencing method used in an exemplary embodiment of this invention , the details are in the following : step 21 , dna is processed into multiple dna fragments , and further constructed into multiple dna tags . details of embodiment of this step will be shown in fig3 and fig4 . step 22 , every single dna tag is amplified , and then processed into single stranded dna . details of embodiment of this step will be shown in fig5 . step 23 , every single dna tag is sequenced by using sequencing anchor with at least one degenerate base . sequencing signal is produced along the sequencing process . details of embodiment of this step will be shown in fig6 , 7 , 8 and 9 . step 24 , sequence of every single dna fragment is obtained based on sequencing signal . details of embodiment of this step will be shown in fig1 . in one exemplary embodiment , step 21 in fig2 , details of dna tags construction based on dna are shown in fig3 , including following steps . step 211 , dna is processed into dna fragments . in this invention , methods of processing dna into dna fragment can vary , such as fragmenting the dna physically , or cleaving the dna by dna enzyme . generally , for long dna fragment , length of dna can be shortened within the range of hundreds of base pairs by random cut . however , for some application , for example , mrna expression profile , certain restriction enzyme site is chosen based on requirement and thus converted dna is cut into dna fragment with sticky ends step 212 , adaptor sequences are ligated to each end of dna fragment . thus dna tags are constructed . adaptor sequences include sequences complementary to general sequence in anchor and sequences for amplification primer . in this invention , anchor is used for sequencing of dna fragment . it is designed according to adaptor sequence . in one optimized embodiment , anchor is called sequencing anchor , including a general sequence and at least one degenerate base . the general sequence is complementary to adaptor sequences in dna tags . as for sequence anchor , details will be described in fig7 , fig9 and exemplary embodiment . in an optimized exemplary embodiment , constructed dna tags are collected and forms a tags library . this can be used in the following sequencing reaction and signal collection . in an optimized exemplary embodiment , besides sequences complementary to general sequence in sequencing anchor , adaptor sequence includes anchor sequence of normalization for sequencing signal , called normalization anchor . in this invention , there are multiple amplification primers . in an exemplary embodiment , amplification primers are pcr primers . in an exemplary embodiment , process of dna tags construction is shown in fig4 . first , dna is processed into dna fragment . at this stage , adaptor sequences need to be designed . it needs to be described that for randomly cut dna fragment , adaptor sequence is designed to have 6 random bases overhanger on its 5 ′ end . this overhanger can be paired with sequences with 6 complementary bases on its 3 ′ ends . as for sticky end dna fragment , adaptor sequence can be designed to have complementary ends that can be ligated with double stranded dna . in this exemplary embodiment , in order to produce dna tags at the same length , the designed first adaptor sequence should have one of type ii restriction enzyme sites . then dna fragments are denatured into single stranded dna . the denatured dna is ligated with first adaptor sequence . thus a ligation reaction is completed . since there is one of type ii restriction enzyme site in the first ligation sequence , through cutting dna fragment ligated with the first adaptor sequence , a small fragment together with the first adaptor sequence is cut off . thus ligated dna fragment can be processed at the same length . dna fragments are immobilized with the first adaptor sequence . their free ends can be repaired to blunt ends and be ligated with the second adaptor sequence . therefore dna tags are constructed with two adaptor sequence . in an exemplary embodiment , step 22 in fig2 , the detailed process of dna tags amplification is shown in fig5 . there are various ways to amplify dna tags in this invention . in this exemplary embodiment , single molecule pcr is used to embody amplification . thus said amplification primers in adaptor sequences of dna tags are pcr primers amplification process in detail includes following steps . in step 221 , pcr primers that are included in adaptor sequence of dna tags are immobilized on vector &# 39 ; s surface . in this invention , said vector can be various forms , such as glass slides , micro - beads and etc . in an optimized exemplary embodiment , this step is to immobilize pcr primers through covalently linked or biotin binding on vector &# 39 ; s surface such as glass slide or micro - beads or etc . in step 222 , vector associated pcr system is partitioned into reactors . each reactor includes an independent dna tag . in this invention , said pcr system includes primers , dna polymerase , dna tags , dntp , buffers and etc . in the above steps , said reactors typically are picoliter reactors . however , in this invention , reactors can be the ones besides the described , for example , can be nanoliter reactors and etc . when said step 221 vectors vary , picoliter reactors in step 222 can differ . in an exemplary embodiment of the above step , when vector is glass slide , process of construction of picoliter reactor is as the following : cover made of soft material and with small holes of picoliter volume is overlaid on the surface of glass slides . thus pcr system is partitioned into picoliter reactors . said soft material can be pdms , and can be made as a cover with small holes of picoliter volume . in another exemplary embodiment of the above step , when vector is micro - beads , process of construction of picoliter reactor is as the following : microbeads are dispersed into pcr system . then pcr system is placed into oil liquid and forms suspend picoliter drops with micro - beads . each picoliter reaction droplet is an independent picoliter reactor . in step 223 , pcr is carried out in picoliter reactor and thus produces multiple copies of dna tags . in step 224 , obtained dna tags are processed into single stranded dna . in an exemplary embodiment , single stranded dna tags can be obtained by alkaline denature of dna tags . it should be stated that if the vector used in this invention is micro - beads , after step 223 , an enrichment process should be included . the process includes ( 1 ) first , dna tags bound on micro - beads are amino - modified ; ( 2 ) then micro - beads are bound to the surface of loading film through amino covalently linked and form an enrichment array . herein , loading film is transparent material that can be used to load samples , such as glass slides , plastics , quartz and etc . in this invention , micro - beads with dna tags are bound to special modified glass slide &# 39 ; s surface using amino chemistry . this method is very efficient . fill factor is near 70 % of its useful surface . it won &# 39 ; t have overlapping problem even with over - loaded micro - beads . more importantly , unbound micro - bound can easily be collected and saved for next experiment and won &# 39 ; t lose their function . in the above process of enrichment of micro - beads , step ( 1 ) methods of amino modification of dna tags on micro - beads can be multiple kinds : in an exemplary embodiment , dna bound on micro - beads can be ligated with amino modified nucleotide . amino modified nucleotide , for example , aa - dutp ( aminoallyl - dutp ), aa - dctp ( aminoallyl - dctp ) and etc . can be independently or together with dntp added into tdt ( terminal transferase ) reactions , thus labeling dna molecules . one option is that dideoxynucleotide can be added at appropriate ration to limit the length of the terminals . in another exemplary embodiment , amino modified oligonucleotide can be dual labeled with psoralen through binding with complementary dna on micro - beads by laser activation . thus dna tags can be amino modified . in the above process of enrichment of micro - beads , step ( 2 ) micro - beads are covalently bound to surface of loading film by amino binding . end of the covalently binding unit can be of amine family or hydroxyl family . this covalent stable immobilization can be the binding of hydrazine with aldehyde or ketone . this covalent binding process can be embodied by covalent binding of one of the several loading film as the following : in the first exemplary embodiment , loading film ( glass or polystyrene ) can be amino modified . after adding carbodiimide such as edc ( 1 - ethyl - 3 -( 3 - dimethyllaminopropyl ) carbodiimide ) and etc ., amino group on loading film can be paired with hydroxyl and forms amino group . in the second exemplary embodiment , loading film ( glass ) is silylated by amino modification . silylated surface includes a silylated film including silane molecules with functional amino group . in the third exemplary embodiment , loading film ( glass ) is modified by silylation . however , the silylated film has the following functional groups : aldehyde , epoxy , amber imine or mixture of the above groups . these functional groups can interact with one or other . this interaction can be covalent or non - covalent . this interaction can be carried out on dna or oligo on micro - beads without modification or with amino modification . in the fourth exemplary embodiment , loading film ( polystyrene ) contains amino group after modification . thus it can bind amino modified oligonucleotide or dna by covalently linked . this modification can be done on micro - beads . surface of amino modified polystyrene is done by hydrazine compounds of aromatic family , such as sanh ( c6 - succinimidyl 6 - hydrazinonicotinate acetone hydrazone ) or shth ( succinimidyl 4 - hydrazidoterephtalate hydrochloride ). dna or oligonucleotide is modified through aldehyde group . sfb ( c6 - succinimidyl 4 - formylbenzoatecan be modified by this aldehyde compound . when the above compound mixed together , hydrazine group interact with aldehyde and transforms into hydrazone compound . it should be stated that , this invention is not limited by the above exemplary embodiments . other similar processing method should be protected by this invention . in an exemplary embodiment , step 23 in fig2 , detailed process of sequencing of dna tags by using sequencing anchor with at least one degenerate base is shown in fig6 . before sequencing , through artificially synthesis method of polymers of oligonucleotides , sequencing anchor should be synthesized into sequencing anchor with k numbers of degenerate bases is operable to hybridize to the dna tags . herein , k is a positive integer , generally within the range from 1 to 20 . the idea is that the complementary strand of the portion of the adaptor sequences in dna tags is used as general sequence of sequencing anchor . then based on this general sequence , k numbers of degenerate bases are added to the end . in this invention , said sequencing anchor with k numbers of degenerate bases can be various sequences , such as extension primer , polymerase extension primer and etc . it should be stated that said extension primer is referred to sequencing anchor that is used by ligase in ligation reaction . polymerase extension primer is referred to sequencing anchor that is used by dna polymerase during sequencing reaction . step 231 is process of hybridization between sequencing anchor with k numbers of degenerate bases and dna tags immobilized on vector &# 39 ; s surface . step 232 , sequencing anchor is extended along dna tags through k numbers of degenerate bases . sequencing signal is produced during extension process . herein , degenerate polymers include multiple forms , such as hexamers , heptamers , octamers , nonamers and etc . moreover , there are multiple ways for degenerate polymers labeling , including biotin labeling , fluorescence labeling and etc . there are multiple ways of fluorescence labeling including 4 color fluorescence labeling , 2 color labeling and etc . take degenerate nonamers as example . method of fluorescence labeling is as the following ( 1 ) if method of 4 color fluorescence labeling nonamers is taken , one set of fluorescent labeling can be used for 3 ′ end and the other set can be used for 5 ′. herein , ligation of degenerate polymers of oligonucleotides should be designed before hand . thus 6 to 7 bases can be called from the ligation site between extension primer and dna tags . then sequencing anchor with k numbers of degenerate ( i . e . k = 6 ) bases is used for further sequencing . in this exemplary embodiment , the length of extended primer is optimized . by using different extension primers with different numbers of degenerate bases , up to 12 bases can be sequenced from the same end . therefore , this method of sequencing can be used to analyze complicated target sequences ( e . g . human genome sequences ). in order to further increase the strength of the output signal , in this invention , a 2 color detection method is in place of 4 color detection method . in 2 color detection method , strong fluorescence labeling can be used , such as cy3 , tamra , texas red , tex613 or etc . in an exemplary experiment , by using ligation mixture of two fluorescence labeled degenerate polymers and two non - labeled degenerate polymers ( e . g . cy3 - a , texas red - g , - t , - c ), sequencing signal of dna tags immobilized on glass slides or micro - beads can be detected . then extension primers and ligated degenerate polymers are removed . mixture of the same extension primer and degenerate polymers different from the above ( e . g . cy3 - t , texas - red - c , - a , - g ) is used to do another sequencing . sequencing signal can be produced . detection of two ligation reaction can obtain a complete set of data information of all 4 bases . in another exemplary embodiment , if sequencing anchor with k numbers of degenerate bases is polymerase extension primer , polymerase , nucleotide , labeled nucleotide ( biotin label or fluorescence label ) are added into polymerase extension primer mix . dna polymerase extends the 3 ′ end of extension primer along dna tags . sequencing signal is produced along extension process . after this step , dna strand extended from extension primer by polymerase should be removed . removal of dna strand can vary , such as denature ( low salt and high temperature ), or exonuclease digestion ( e . g . λexonuclease ) or enzyme accompanied denature ( e . g . when dutp is used in extension mixture , enzyme could be uracil - dna glycosylase or dna glycocylase , and endonuclease viii ). in an optimized exemplary embodiment , in order to increase the sequencing accuracy , said step 232 can adapt overlapping sequencing mechanism or type iis restriction enzyme walking mechanism . details are ( 1 ) in overlapping sequencing mechanisms , with sequencing anchor in both ends , dna tags can be sequenced bi - directionally from both ends . sequence can be called bi - directionally . ( 2 ) in type ii restriction enzyme walking mechanism , by using type ii restriction enzyme site in the first adaptor sequence of dna tags , portion of sequenced dna tags is cut off . new adaptor sequence is ligated to type ii restriction enzyme site . thus new dna tags are constructed . sequencing is continued by using new adaptor sequence . sequencing results of the remaining region in said dna tags can be obtained afterwards . in another optimized exemplary embodiment , as shown in fig8 and fig9 . if normalization anchor is included in the adaptor sequence of dna tags , then when step 232 is carried out , normalization anchor in adaptor sequence is ligated with labeled oligonucleotide polymers . normalization signal is produce . thus in following data processing , reaction efficiency of multiple cycles can be normalized . thus difference between each reaction can be eliminated and the accuracy of sequencing can be raised . in an exemplary embodiment , fig2 step 24 , the detailed process of sequencing signal collection , data processing and sequence of dna tags calling is shown in fig1 , including following steps . in an optimized exemplary embodiment , when said step 232 is performed and normalization signal is produced , normalization signal is collected at the same time as step 241 is conducted . normalization signal is that used to normalize collected sequencing signal . difference between different reactions is eliminated . in an exemplary embodiment of this invention , normalization is embodied by the ratio of sequencing signal versus normalization . for example , signal no . 1 is x and signal no . 2 is y and normalization signal is m . sequencing signal after normalization is x / m and y / m separately . in step 242 , different bases are called according to different sequencing signal , i . e . said sequence of dna tags . in this invention , according to discrete characteristics of base complementary , type of bases is determined in dna tags . fig1 is a flow chart illustrating dna sequencing method in an optimized embodiment of this invention . this embodiment is an optimized embodiment , the application exemplary is extension primer to sequencing anchor primer , micro - beads to vector . step 1102 , adaptor sequences are added to both ends of dna fragments and then digested into dna tags of equal size . step 1103 , pcr primers included in adaptor sequence of dna tags is immobilized on the surface of micro - beads . step 1104 , micro - beads is dispersed into pcr system , and then the pcr system is dispersed into oil and formed the suspend picoliter reactor droplets which are picoliter reactors . step 1105 , pcr amplify in picoliter reactors , then process the obtained dna tags into single stranded dna , and then enrich the micro - beads . step 1106 , hybridize between extension primer containing k number of degenerate bases and dna tag immobilized on vector surface . step 1107 , extension primer and degenerate polymers with fluorescent end label are made ligation reaction , then extended and sequencing signal is produced . step 1108 , normalized anchor primer is used to do ligation reaction , and produced normalizing signal . step 1109 , sequencing signal and normalized signal are collected and normalized by optical imaging . step 1110 , sequences of different bases which are dna tag fragments are called based on sequencing signal . an exemplary embodiment of the above optimal selection in fig1 : hybridization between extension primer and dna tag , that is the extension primers matching the sequencing anchor of the tag directly . then the extension primer have ligation reaction with a set of degenerate nonamer labeled fluorescence ( nnnnnnnnn ) the degenerate nonamer is mixed by 4 kinds of nonamers . to read the sequence of the base , in some site , the types x of the base in the 4 kinds of nonamers , have the same type of the fluorescence - labeled . ( eg nnnxnnnnn , x = a , t , c , g ) because of the resolution characteristics of the ligase &# 39 ; s base complementary in x site of the nonamer , the type of the base in the sequence of tag can be inferred . because extended primer contains k number of degenerate bases ( ie . k = 1 , 2 , 3 , 4 , 5 , 6 ), the sequence in dna tag can be read by different number of degenerate base and the same set of nonamers ( i . e . xnnnnnnnn , x = a , t , c , g ). or can use different set of extended primer and nonamer to read the base sequence located in the same site . the most important characteristics of the methods used in this invention is that longer sequence of fragment can be called from dna tags , for instance , 13 continuous bases . current technology can only distinguish only within the sixth or seventh base of a fragment by ligase . in this invention positions beyond the tenth base from the point of extension primers on both ends can be called . by using the above methods , more than 20 bases of sequence can be called from 5 ′ or 3 ′ end to the binding point of sequencing anchor with dna tags . thus this method can be used for sequencing longer dna tags generated by certain type ii restriction enzyme ( such as mmei , ecop15i or etc .). besides , designed indented primer series is also included in this invention . indented primers are sequencing anchors shorter than the primer sequence of the tag sequence , for example , indenting to − 3 , − 2 , − 1 position relative to the starting point of the unknown tag sequence . by using these indented primers , dna tag sequence can be called using only one set of degenerate nonamers . for example , for nnnxnnnnn , if the fourth position is designed corresponding to 4 different agct in primers , then from the first to tenth base of dna tags can be called . fig1 is a flow chart illustrating dna sequencing method in another optimized embodiment of this invention . this embodiment is another optimized embodiment , wherein polymerase extending primer to sequencing anchor primer and glass slide to vector . the details are in the following : step 1202 , adaptor sequence is added to both ends of dna fragments and then digested into dna tags of equal size . step 1203 , pcr primers included in adaptor sequence of dna tags are immobilized on the surface of glass slide . step 1204 , a cover having picoliter volume holes is put over a glass slide , and thus the pcr system is compared into picoliter volume reactors . step 1206 , hybridize between extension primer containing k number of degenerate bases and dna tag immobilized on glass slide surface . step 1207 , dna polymerase and nucleotide are added in dna polymerase extending nucleotide , so extending dna polymerase extended and sequencing signal is produced . step 1208 , sequencing signal is collected by optical imaging . step 1209 , different bases are called based on different sequencing signal . in one of the optimized embodiment shown in fig1 , process of sequencing using dna polymerase extending primer to be sequencing primer will be shown in fig1 : in this exemplary embodiments dna polymerase extending primer includes the sequence complementary to anchor primer sequence in dna tags , dna polymerase extending primer also contains k number of different length degenerate bases and 3 ′ end of dna polymerase extending primer contains specific bases ( a , t , g , c ). dna polymerase extending primer is used to hybridize with dna tag immobilized on vector surface ( micro - beads or glass slide ). when dna polymerase added , the 3 ′ end of primer hybridizing with dna tag is extended . because of selectivity of dna polymerase , the primer containing complementary bases to dna tag at 3 ′ end can extended along tag template and produce signal . when mixing labeled nucleotide into extending mixture , dna tag extended correctly can be recognized correctly . otherwise the primer not containing complementary bases can not be extended , therefore will not produce signal . according to the theory of base specification the anchor primer containing different base on its 3 ′ end can be applied in this dna tag , therefore deduce the sequence of different dna tag based on different signal labeled on each dna tag . the number of complementary bases ( ie . k = 1 - 9 ) may decide the information of the base located in k + 1 position downstream anchor dna tag . for example , the primer constructed as “ anchor primer - nnn - a / t / g / c ”, can decide the base located in 4 base downstream the anchor primer , which means the 4th base . this invention provides two exemplary embodiments . details are as the following : example one is the scenario of sequencing by using extension primer . in this exemplary embodiment , dna to be sequenced is processed dna fragments with adaptor sequences on both ends and a normalization sequence . sequence of short dna tags is 5 ′- ccactacactggtact cctcatcgatgacgtacgact - cgattacgaatcg - ctagcattcgga ctcgatacgaagtcgatcgatgaga - 3 ′ ( seq id no : 1 ). among the sequence , 5 ′- cctcatcgatgacgtacgact - 3 ′ ( seq id no : 2 ) is the adaptor portion of dna tags . its complementary strand ( 5 ′- agtcgtacgtcatcgatgagg - 3 ′) is the general sequence in sequencing anchor . sequencing anchor is synthesized according to said general sequence with additional degenerate bases ( e . g . k = 1 - 9 ). for example , in 5 ′- agtcgtacgtcatcgatgaggn - 3 ′ ( seq id no : 5 ), there is one degenerate base . 5 ′- cgattacgaatcg - 3 ′ ( seq id no : 6 ) is a dna to be sequenced 5 ′- cgatacgaagtcgatcgatg - 3 ′ ( seq id no : 3 ) is normalization sequence in sequencing anchor . for this dna to be sequenced , the detailed experimental operation of sequencing is as the following : ( 1 ) dna is copied into multiple copies by single molecule pcr and immobilized on surface of micro - beads . after basic denature of dna tags , single stranded dna is obtained and immobilized on surface of micro - beads on its 5 ′ end . ( 2 ) by covalently amino linked , micro - beads are immobilized on the surface of glass loading film . thus dna tags to be sequenced are immobilized on the same level . ( 3 ) sequencing anchor ( 5 ′- agtcgtacgtcatcgatgaggn - 3 ′ ( seq id no : 5 )) and normalization anchor ( 5 ′- catcgatcgacttcgtatcg - 3 ′ ( seq id no : 4 )) are hybridized with single stranded dna in hybridization buffer ( such as ssc , sspe or etc .). temperature of the system is first raised ( 50 - 80 ° c .) and then followed by a graduate drop . thus correct pairing between template and two anchors is obtained . ( 4 ) after replacing reaction buffer with ligation buffer , ligase and fluorescent labeled oligonucleotide polymers and fluorescence labeled normalization polymers are all added in . reaction temperature is controlled within the range between 20 ° c . to 30 ° c . time of reaction is 1 minute to 30 minutes . ( 5 ) remains of non ligated reactant is washed off and is replaced by washing buffer . ( 6 ) for fluorescent optical imaging of micro - beads , corresponding bases sequenced by anchor and oligonucleotide are recorded . normalization signal is recorded as well . ( 7 ) after buffer is replaced , enzyme mixture is added to remove extended dna . enzyme used can be for example uracil - dna glycosylase ( udg ) or mixture of udg and endonuclease viii . when the reaction temperature is raised to 30 ° c .- 37 ° c . for 1 to 10 minutes , u position amid of sequencing anchor can be cut off . ( 8 ) after buffer is replaced by denaturing buffer , when system temperature is raised to 45 ° c .- 65 ° c ., the short ligated dna strand is removed and dna is recovered into its original single stranded status . ( 9 ) by choosing different anchor ( anchor with different numbers of degenerate bases e . g . 5 ′- agtcgtacgtcatcgatgaggnn - 3 ′ ( seq id no : 7 ) and 5 ′- agtcgtacgtcatcgatgaggnnn - 3 ′), and depending on the characteristics that different position correspond to different oligonucleotide polymers , sequencing information can be obtained from the same reaction steps involving bases at other positions in dna tags . in this exemplary embodiment , the ultimate sequence called is 5 ′- cgattacgaatcg - 3 ′ ( seq id no : 6 ), same as the original sequence of dna fragment to be sequenced . example two is the scenario of primer extension by polymerase . in this exemplary embodiment , dna to be sequenced is processed dna fragments with adaptor sequences on both ends and a normalization sequence . sequence of dna tags is 5 ′- ccactacactggtact cctcatcgatgacgtacgact - cgattacgaatcg - ctagcattcgga ctcgatacgaagtcgatcgatgaga - 3 ′ ( seq id no : 1 ). among the sequence , 5 ′- ctagcattcgga - ctcgata - 3 ′ ( seq id no : 10 ) is the adaptor portion of dna tags . its complementary strand ( 5 ′- tatcgagtccgaatgctag - 3 ′ ( seq id no : 8 )) is the general sequence in sequencing anchor . sequencing anchor is synthesized according to said general sequence with additional degenerate bases ( e . g . k = 1 - 9 ) and additional positioning base on 3 ′ end . for example , as for the base at the third position of the sequence to be sequenced , a set of 4 sequencing anchors , composed of 5 ′- agtcgtacgtcatcgatgaggnn ( a / t / c / g )- 3 ′ series are used to sequence any dna sequence derivatives using 5 ′- cgattacgaatcg - 3 ′ ( seq id no : 6 ) as the portion to be sequenced . for this dna to be sequenced , the detailed experimental operation of sequencing is as the following : ( 1 ) dna is copied into multiple copies by single molecule pcr and immobilized on surface of micro - beads . after basic denature of dna tags , single stranded dna is obtained and immobilized on surface of micro - beads on its 5 ′ end . ( 2 ) by covalently amino linked , micro - beads are immobilized on the surface of glass loading film . thus dna tags to be sequenced are immobilized on the same level ( 3 ) sequencing anchor ( 5 ′- tatcgagtccgaatgctagng - 3 ′ ( seq id no : 9 )) is hybridized to sequencing template in hybridization buffer ( such as ssc , sspe or etc .). temperature of the system is first raised ( 50 - 80 ° c .) and then followed by a graduate drop . thus correct pairing between template and two anchors is obtained ( 4 ) after replacing reaction buffer with polymerase buffer , polymerase , fluorescence labeled nucleotide and regular nucleotide are all added in the reaction system . reaction temperature is controlled within the range between 20 ° c . to 30 ° c . for 1 to 10 minutes . ( 5 ) remains not to react is washed off and is replaced by washing buffer ( 6 ) for fluorescent optical imaging of micro - beads , micro - beads with extension at the end are recorded . since extension only occurs when the end of sequencing anchor is correctly paired with dna fragment to be sequenced ( in this example , g is on sequencing anchor and c is on the sequence to be tested ), signal is recorded for the base in dna fragment corresponding to the end of sequencing anchor . if sequencing anchors other than the correct one is chosen , base pairing can &# 39 ; t be correct and extension won &# 39 ; t happen . thus base at the position to be sequenced can be correctly called . ( 7 ) after buffer is replaced , enzyme mixture is added to remove extended dna . enzyme used can be for example uracil - dna glycosylase ( udg ) or mixture of udg and endonuclease viii . when the reaction temperature is raised to 30 ° c .- 37 ° c . for 2 to 10 minutes , u position amid of sequencing anchor can be cut off . ( 8 ) after buffer is replaced by denaturing buffer , when system temperature is raised to 45 ° c .- 65 ° c ., the newly synthesized dna strand is removed and dna is recovered into its original single stranded status . ( 9 ) similar method using sequencing anchor with ends of three other bases is adapted to sequence dna fragment . after testing all 4 sequencing anchors corresponded to different bases , the correct base can be called in the template sequence corresponding to the base at the end of sequencing anchor . ( 10 ) by choosing sequencing anchors with different numbers of degenerate bases ( e . g . 5 ′- tatcgagtccgaatgctagnn ( a / t / c / g )- 3 ′, 5 ′- tatcgagtccgaatgctagnnn ( a / t / c / g )- 3 ′), sequencing information can be obtained by using same reaction steps at different base positions at template . in this exemplary embodiment , the ultimate sequence to be called is 5 ′- cgattacgaatcg - 3 ′ ( seq id no : 61 same as the original sequence of dna fragment to be sequenced . fig1 is a diagram of images obtained in the above two exemplary embodiments . base g is called by cy3 labeled polymers in this test . density of the sample is very high and signal to noise ratio is very high too . experimental conditions are 10 × objects , na = 0 . 3 , 100 w mercury lamp , ccd 2 s exposure . fig1 shows system structure of dna sequencer in an exemplary embodiment of this invention , including unit of short tags construction 10 , unit of amplification 20 , unit of sequencing reaction 30 , unit of signal processing 40 . ( 1 ) unit of short tags construction 10 . aiming to process dna into multiple dna segments , and then constructed into multiple dna tags . ( 2 ) unit of amplification 20 . connected to unit of short tags construction 10 , every single dna tag is amplified . ( 3 ) unit of sequencing reaction 30 . connected to unit of amplification 20 , by using sequencing anchor which is operable to hybridize to the dna tags and contains at least one degenerate base , every single dna tag is sequenced and sequencing signal can be produced . in an exemplary embodiment , said unit of sequencing reaction 30 includes : a . reaction chamber . vector is placed on one of its inner wall . multiple dna tags are immobilized on said vector &# 39 ; s surface . receiving sequencing reaction reagents , sequencing of said dna tags can be conducted in reaction chamber , and producing sequencing signal . b . reagent entry and exit are separately placed at the ends of the other side of the inner reaction chamber wall . both are provided channels separately for reaction reagent entering and for reaction reagent exiting . in this invention , reagents used in sequencing reaction includes ligase and fluorescence labeled oligonucleotide or polymerase and fluorescence labeled oligonucleotide ( 4 ) unit of signal processing 40 connected to unit of sequencing reaction 20 , aiming to obtain sequences of every single dna fragment from sequencing signal . in an exemplary embodiment , as shown in fig1 , unit of signal processing 40 includes : a . data collection module 41 , used for collecting said sequencing signal . b . data processing module 42 , used for calling sequence of every single dna fragment based on sequencing signal . in an exemplary embodiment , data collection module 41 includes imaging components and reader . imaging component can be large scale of ccd detector , for example , 4 to 11 million pixel ccd detectors . thus high speed data collection can be embodied and throughput of all data can be raised . all of the above is relative optimized embodiment in this invention , and is not to limit this invention . any modification , equivalent replacement , optimization or etc . within the soul and principle of this invention is all included in the protection range of this invention .