Relevance. DNA analysis is currently one of the most accurate and informative methods in medicine, forensics, and molecular genetics. The success of the analysis largely depends on the quality of the isolated DNA, so choosing the optimal extraction method is crucial for obtaining reliable results.

Objective: is to conduct a comparative analysis of the efficiency of DNA extraction by chloroform-phenol and column methods.

Materials and methods. The study included 94 blood samples from the biobank of the Research Institute of Genetic and Molecular Epidemiology, KSMU. Genomic DNA was isolated from the blood using the chloroform-phenol and column methods, using the ExtractDNA-2 reagent kit (NOMOTEK, Russia). The concentration and purity of the obtained DNA samples were analyzed using a NanoDrop2000 spectrophotometer (ThermoFisherScientific, USA). Statistical analysis was performed using Statistica v.13.0 (StatSoftInc., USA).

Results. Analysis of the distribution of concentration and purity of two groups of samples, performed using the Kolmogorov-Smirnov test, revealed that the DNA concentration values ​​in the first (obtained by phenol-chloroform extraction) and second group of samples (obtained by the column method), as well as the purity values ​​of the DNA solutions of the second group, had an abnormal distribution (P<0.01), whereas the distribution of the purity values ​​of the DNA solution of the first group of samples did not differ from normal. It was found that the median concentration of DNA obtained by phenol-chloroform extraction was 119.50 ng/μl (Q1=89.10; Q3=182.20) and statistically significantly exceeded the median concentration of samples of the second group: Me=39.05 ng/μl (Q1=26.80; Q3=54.10, P=3.69×10^-16). Moreover, the median purity A 260/280 of DNA solutions for the first group of samples (Me=1.69 (Q1=1.65; Q3=1.74)) was lower than that of the second group of samples: Me=1.84 (Q1=1.80; Q3=1.87, P=1.99×10^-15).

Conclusion. A comparison of the two methods for DNA extraction from blood revealed that phenol-chloroform extraction gives a significantly higher DNA yield, but is inferior to the column method in terms of solution purity.