The possibilities of early detection of chronic myelo-proliferative tumors (MPT) are determined by sensitivity of techniques implemented for finding somatic mutation V617F in gene JAK2. The mutation V617F can also be found in individuals without unfolded picture of hematological diseases. The detection of mutation even in low concentrations is associated with increasing of risk of cerebral stroke and thrombosis of arterial and venous vessels. The study was carried out to develop techniques based on COLD polymerase chain reaction and allele-specific polymerase chain reaction targeted to increasing of sensitivity of finding mutation V617F detected using pyro-sequencing. The analytical sensitivity of techniques was evaluated by control samples with different ratio of alleles. For allele-specific polymerase chain reaction analytical sensitivity amounted to 0.25% of mutant allele at concentration of analyzed control sample 10 copies of DNA per mkl. For COLD polymerase chain reaction sensitivity amounted to 0.5% at concentration 10 copies of DNA per mkl. The comparative approbation of techniques was implemented using clinical material obtained from 106 patients with suspicion on MPT. The analysis of clinical samples using COLD polymerase chain reaction revealed 13 (14%) and using technique of allele-specific polymerase chain reaction - 15 (16%) positive samples. In all 15 cases of detection of mutation clinical confirmations of diagnosis of MPT was received. The proposed techniques permit increasing efficiency of amplification of mutant DNA in analyzed samples and hence to increase sensitivity of subsequent analysis of products of amplification using technique of pyro-sequencing. Therefore, the mentioned techniques can be recommended to be applied for confirmation of diagnosis of MPT and early identification of individuals with increased risk of development of venous and arterial thromboses.