Thermal cycling consisted of initial denaturation at 95 C for 2 min followed
by 25 cycles of denaturation at 95 C for 30 s, annealing at 55 C for
30 s, an extension at 72 C for 30 s, with a final extension of 5 min
at 72 C. Replicate amplicons were pooled and visualized on 2.0%
agarose gels using a SYBR Safe DNA gel stain in 1 TAE.
After purification using a spin column (QIAGEN, Düsseldorf,
Germany), DNA fragments with ligated adapter molecules on both