STR typing of fixed human tissue: Formalin vs. an alcohol-based method

In this study, we evaluated the effect on DNA typing of storage of human tissue in formalin versus an alcohol-based method (Complucad®). Samples of tissue were collected at different time from fixation. DNA was isolated and, after quantitation, was amplified by quadruplex PCR including four STR loci (LPL, F13B, FESFPS and F13A01). For alcohol-fixed tissue, quantitation showed that DNA yield remained unchanged regardless of storage time and complete profiles were obtained. Instead, the DNA amount recovered from those fixed with formalin was lower and DNA looked very degraded. Actually, for these samples, we observed a lack of amplification of >200 bp loci.