Amplification of medium-size GC-rich DNA fragment using whole blood as a source of the template. 806 bp fragment of human Q8N1R6 gene (73.3% GC) in heparinized human blood (2% final concentration) was amplified in PCR mix II containing various concentrations of trehalose (0.1 - 0.3 M) and 1,2-propanediol (0.5 - 1.0 M). Position of the specific product (Fr. 8) is shown by an arrow. A typical result of three independently performed experiments is shown.