5 and 6 Fam (or 5 and 6 Tamra) have no spectral difference, only a slightly difference in orientation when labeled onto oligonucleotide. When you run gel electrophoresis, do 5 and 6 Fam (or 5 and 6 Tamra) labeled DNA fragments of the same size(length) have significant mobility difference? I will guess very slight difference.

Anybody has experience?

Thank you very much!