his study aimed to overcome false - positive in detection of tumor micrometastases by reverse transcriptase - polymerase chain reaction (RT - PCR)

Using this method

the authors amplified cytokeratin 19(CK19) mRNA in histologically involved regional lymph nodes of 40 patients with non - small - cell - lung - carcinoma and 20 with esophgus cancer. In addition

they amplified CK19 mRNA in DNase - pretreated normal nodes of 10 . respectively. They could find out the interference of CK19 pseudogene by performing nontranscribed RNA and genomic DNA controls. This influence could be eliminatde by treating the RNA samples with DNase before complement DNA were synthesized. Using nested RT- PCR method

they could find the presences. of illegitimate transcription of CK19 gene in DNase - pretreated normal nodes.It is a suitable measure to remove this false - positive result that regulate the sensitivity of method to distinguish the normal and involved lymph nodes exactly.