Primer design Most imp (length: 2030bp (2)G+C contents: ATCG random distributed (3)primers: no complementary sequence (4 3end of the primer: no modification (55end of the primer: product length, can be modified (6 specificity: less than 70% homolo gy with non-specific amplification sequence, or 8bp continuous complementary basePrimer design Most imp. (1)length: 20～30bp (2)G+C contents:ATCG random distributed (3)primers : no complementary sequence (4)3‘end of the primer: no modification (5)5‘end of the primer:product length，can be modified (6) specificity:less than 70% homology with non-specific amplification sequence, or 8bp continuous complementary base