The present work aimed at comparing five different methods of DNA extraction of samples from archived materials (paraffin-embedded tissues, peripheral blood smears - stained or not with Leishman, aspired bone marrow smears and Guthrie card bloodspots) and from rare sources (oral cells, one and three capillary bulbs, 2 mL of urine), to evaluate the ease of application and the possibility of amplification of this DNA by the polymerization chain reaction (PCR) technique. The methods included proteinase K digestion - followed or not by phenol/chloroform purification, Chelex 100® (BioRad), InstaGene® (BioRad) and boiling in the sterile water. The DNA obtained was tested for amplification of three genic fragments: the brain-derived neutrophic factor gene (764 bp), the Factor V Leiden gene (220 bp) and the Abelson gene (106 bp). According to the gene fragment length studied, the DNA potential source and the extraction method used, the results characterized the best way to standardize technical procedures to be included in the Standard Operational Procedure Manual of the Molecular Biology Laboratory of the Blood Center in the Medicine School of Unesp, Botucatu, Brazil.
Archived material samples; rare sources; DNA extraction; PCR
