"We performed cDNA RDA using wild-type cDNA as tester and a mixture of cDNAs from three different
mec-3 mutant strains, CB1498, TU6, and TU656, as driver (see Section 3). Difference products were dramatically enriched for the known
mec-3-dependent genes -
mec-3,
mec-4,
mec-7 and
mec-18 - after two and three rounds of subtraction and polymerase chain reaction (PCR) (Fig. 1)... cDNA from a fourth round of RDA showed an increase in representation of
mec-7 and
mec-18 and a decrease in that of
mec-3 and
mec-4 (data not shown)."