For the purpose of DNA isolation prior to genetic analysis two samples of peripheral blood will be taken. Tubes with sampled material will be stored under temperature of 2 - 8°C and in the least possible time delivered to the laboratory where DNA will be isolated. Of all the samples delivered to the laboratory, DNA will be extracted using the automated isolation method. From the second sample related to the genetic analysis also the plasma will be obtained and stored at -20°C. The DNA sample is then divided into two aliquot parts which will be stored separately for future analysis in order to decrease the risk of their impairment. DNA isolated from cells of biological material will be properly stored prior to further analysis. DNA will be archived by its freezing to -80°C, a temperature in which the characteristics are maintained for several decades.