We compared two technologies of real-time PCR (with the use of fluorescent SYBR Green I dye and specific TaqMan probe) for quantification of the dose of her2 gene in breast tumors. The maximum increase in the gene dose in TaqMan and SYBR Green I analyses was 10- and 5-fold, respectively. In was found that TaqMan and SYBR Green I technologies allow detection of the matrix in amounts corresponding to 1-100 and 2.5-40.0 ng genomic DNA, respectively. Tenfold increase in the gene dose leads to incorrect evaluation of multiplication ratio in the SYBR Green I analysis. These results suggest that TaqMan technology is more preferable for correct evaluation of her2 gene dose.