Amplification of genomic DNA fragments in various combinations of PCR mixes and DNA dyes. Isolated genomic DNA was diluted to contain 47 (1), 141 (2), 423 (3) 1269 (4) or none (Control; C') copies of Thy-1 gene per one μl of different PCR mixes (I - IV) supplemented without (A) or with (B - H) various DNA-binding dyes. The samples were analyzed by PCR (A) or qPCR (B - H) followed by agarose gel electrophoresis; DNA fragments were visualized by ethidium bromide staining. Migration of the specific DNA fragment (864 bp) is indicated by an arrow (Fr. 1). Regression coefficients (R2) and efficiencies (E) were calculated from plots of Cq values versus log copy numbers, and are presented only for samples with the expected melting temperature at all template dilutions. All samples were analyzed in 3 - 7 independent experiments with similar results.