What is the difference between 17 bp and 20 bp MPSS signatures?
The signatures in our MPSS libraries were sequenced to both 17 bp and 20 bp; the 20 bp signatures are exactly the same libraries with a simple 3 bp extension of sequence from every bead in the library. While 20 bp is longer and should therefore provide more specificity for some genes, the extra 3 bp also slightly increases the probability of failure of the sequencing reaction due to palindromic sequences in the signature. We are currently investigating the difference between the 17 and 20 bp signatures and should have more details in the future.
