Effects of DMSO, glycerol, betaine and their combinations in detecting single nucleotide polymorphisms of epidermal growth factor receptor (EGFR) gene promoter sequence in non-small-cell lung cancer (NSCLC) patients.

The aim of the study was to examine the effects of frequently used polymerase chain reaction (PCR) additives DMSO, glycerol and betaine on amplification of GC-rich epidermal growth factor receptor (EGFR) gene promoter region, in order to detect the presence of -216G>T and -191C>A gene variations in non-small-cell lung cancer (NSCLC) patients. PCR products and restriction fragments were detected by electrophoresis on 8% polyacrylamide gel and 3% agarose gel. Our analysis shows that single used additives including DMSO in concentration of 7% and 10%, glycerol in concentration of 10%, 15% and 20%, as well as betaine in concentration of 1M, 1.5M and 2M significantly enhanced the yield and specificity of PCR reaction. In addition, the combination of 10% DMSO with 15% glycerol has shown positive effects, whereas other analyzed combinations of additives failed to amplify the EGFR promoter region.