Estandarización de un método para la extracción de DNA a partir de muestras clínicas parafinadas

molecular epidemiology includes genotypic studies of different biological processes, including pathological diseases such as cancer. therefore, the paraffin-embedded clinical samples analysis is very important for diagnosis, prevention and therapy. previously, many problems associated with amplification of dna obtained from paraffin-embedded tissue samples were reported. this paper compares the capability of nine methodologies for dna extraction from paraffin-embedded clinical samples, amplifying it by pcr to analyze under-250-bp fragments corresponding to folate pathway enzymes polymorphisms. modification of "salting-out" method with concentrations of 0.5 m nacl and 2 % ctab detergent and proteinase k was the most suitable for amplifiable dna obtention of selected amplicons. all methods showed better amplification with longer cycles and lower annealing temperatures as compared to less fragmented dna samples.