Analysis of hybridization probes for DNA genotypescopy (DNA genotyping and genome fingerprinting) was performed to detect 21 cases of paternity testing. A system with the highly informative multilocus DNA probe Red4, isolated by us earlier, and two single-locus probes (YNH24 and CMM101) detecting highly polymorphic (H > 96%) loci D2S44 and D14S13 was tested. In the cases analyzed, the Red probe was shown to detect, on average, 19.28 +/- 3.6 polymorphic BsuRI fragments in the DNA profile of presumable fathers and 19.67 +/- 5.84 BsuRI fragments in the DNA profile of mothers. The average number of DNA fragments inherited by a child from either parent was approximately equal (8.72 +/- 3.77 and 7.11 +/- 2.66, respectively). The low population frequency of DNA fragments detected by the Red4 probe allowed highly effective positive paternity identification to be performed. Paternity was established in 86% (with probability > 99.75 or > 99.99%) and excluded in 14% of expertises. Single-locus probes YNH24 and CMM101 were used as an additional criterion in cases when, in the DNA profile of a child, a single band (probable de novo mutation) or several bands (probable false paternity or maternity) were revealed but absent in both presumable parents. In once case, a de novo mutation for the YNH24 probe, not described earlier, was revealed. Therefore, a combination of multilocus and single-locus hybridization probes appeared to be the most promising method for significant paternity testing in forensic and medical genetic practice.