The aim of this study was to compare and select the optimal method of DNA isolation from blood, semen and saliva stains, as well as to determine appropriate conditions for employing amplification kits for identification of individual persons [brak w polskim tekście]. The materials analyzed in this study consisted of stains of blood, semen and saliva samples stored for a year, and stains of blood stored for a month. Seven various methods of isolation were compared: the Fast DNA kit (Qbiogene), phenol/chloroform extraction, Sherlock (DNA II Gdansk), Dneasy (Qiagen), Wizard Genomic Purification Kit (Promega), Chelex 100 (Biorad) and salting out proteins method. After the isolation, the quantity of DNA was measured with QuantiBlot [brak w polskim tekście]. The highest DNA concentration in bloodstains stored for one year and one month was observed employing the salting out proteins method. The phenol-chloroform extraction method was also found to produce reasonably good results. Isolation from blood and semen with salting-out method appeared to be the most effective. The phenol/chloroform method was dependent on the age and origin of the materials [brak w polskim tekście]. The Sherlock kit was proven to be effective in blood samples stored for one year. DNA concentration values obtained in semen and saliva samples were very low and characterized by a low repeatability.