Comparative study of two dna extraction methods in different tissues and conditions of degradation

Abstract The aim of tis study is to compare two methods of extraction of DNA from different tissues (spleen, liver, lungs, kidney, hearth, mussles, and pancreas) with Ph–CL and QIAAamp ® DMNA Mini kit and to confirm which of this two methods give better results. Degradation of the tissues was in 3 controled conditions in a period of 6 months: room temperature, in a refridgerator on +4 and outside temperature in a period 2.3–7.8.2010 year. In total 210 analyses were performed and 20–30mg of the tissye was taken. Quantification was performed with Quantifiler kit on 7500 RealTime PCR ABI and analysed with 7500 System SDS version 1,2,3 software. Continuosly temperature was measure with digital TESTO termomethers on each 2h. Comparation of the two extraction protocols from the tissues was performed with T-test. Comparation of different tissues who were degradated in 3 controled conditions and extracted in 5 periods was performed with AMOVA. This study show that biger yeld of DNA from the tissues can be isolated with PhCl extraction method, but also with QIAAamp ® DNA Mini kit eaven there is les amount of isolated DNA it can be used for further PCR reaction. PhCl method its slow, cancerogenous, more expenicve and can be problem in amplification proces because of big amount of DNA. Comparative results from different tissues show that there is no big diferences in the extracted yeld of DNA. We proved that in putrefied tissues non toxic and fast method can be used for DNA extraction. Our study show that there in no decerasing of isolated DNA with increasing of PMI and ambiental temperature, maybe because of the short period of 6 months that we analyse. Althout in forensic DNA analysis we should take in mind that quality and quantity of extracted DNA depends of ambiental conditions, PMI and type of the tissue. The fastes degradation hapends in tissues who have more proteolotyc enzymes.