an rna amplification method is particularly useful for diagnosing bacterial or viral infections or genetic disorders and for cell typing . the method includes the steps of denaturing a solution containing rna , synthesizing a first cdna strand from a suitable primer in the presence of reverse transcriptase , denaturing the heteroduplex formed , synthesizing a second cdna strand from a second primer in the presence of dna polymerase and then subjecting the cdna formed to a sufficient number of amplification cycles . all the reactants and solvents are first placed in the same container to provide a single manipulation step that avoids the risk of contamination .