( c ) when the lymphocytes were centrifuged and placed in a new medium several times in a row , a similar amount of extracellular dna was isolated from each of the successive supernatants , whereas if , after centrifugation , the lymphocytes were put back in their original medium , no increase in the amount of extracellular dna was observed , suggesting an active regulatory mechanism independent of a mechanical effect ;
C0000702
a
C0012854
dna