Recently, we upgraded our Applied Biosystems (ABI)3100 DNA Sequencer to an ABI3130XL system. We are sequencing with 50cm capillaries and POP7 polymer.
When running sequencing reactions (BigDye v3.1), we generate profiles with following characteristic: at the end of the sequence we often registrate an A-peak with (very) strong intensity >> the more when sequence length is shorter. This problem is observed with XTerminator and other purification technologies.