We have also experienced a multiple T problem. We were sequencing PCR
products on a beckman 2000xl, and kept getting unclear reads after the
multi-T site. We then cloned the product site on this and related species.
For the few we were successful with actually had a distribution of
Ts ranging from say 13-19 in the population taken from cryostorage. Those
with even longer multi-T reads were not resolvable. We also tried
resolution with a gene scanned based approach. I belive this could either
be a hypervariable site, or just a problem with t ended priming, such as
slippage. I have recently read that primers with a T end are worse. I
wonder if there is a connection.
Roger E Morey
CDC NCID/DBMD/MSPB
MS G34 Bldg17 # 2205
1600 Clifton rd
Atlanta, GA 30333
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