From: DATFAP: A Database of Primers and Homology Alignments for Transcription Factors from 13 Plant Species
Primer length, round 3
16 – 28 nucleotides
Product length, round 3
80 – 200 nucleotides
Max. primer melting temperature diff., round 3
4.0 °
Max. base repeat, round 3
4 (e.g., GGGG in a primer is allowed, although not in the 3'-end)