Fig. 1

“Panhandle” SMRT-BS. a Computer simulation of primer performance in conventional and bisulfite PCR. The left panel shows the ability of primers to form primer-dimers with P1 = PAIR_ANY_TH and P2 = SELF_ANY_TH parameters of the primer3 output. The right panel demonstrates a tendency of the non-specific annealing by the log₁₀ number of BLAST hits at 3′-ends of the primers. Further details are available in Additional file 1: Supplementary Note 1. b Photography of agarose gel electrophoresis of different long bisulfite PCR products. The lanes are numbered as follows: 1–4 —conventional bisulfite PCR (with specific primers without the “panhandle”), 5–9—“panhandle” bisulfite PCR with the “panhandle” U1 primer as described in the “Methods” section; 1–8 with bisulfite-converted DNA, 9—without the template; 1, 5—without specific primers; 2, 6—the AHRR target; 3, 7—the ALPPL2 target; 4, 8—six-target multiplex PCR. M—DNA ladder marker. c Scheme of the “panhandle” SMRT-BS approach