I've been using (and reusing) Centri-sep columns with my own sephadex G-50
to remove Big Dye terminators. I've been reusing them a lot with
tremendous success but recently ran a very bad gel (multiple peaks in
nearly all lanes). I'm starting to think that the columns can only be
reused a certain amount of times before they accumulate perhaps some
threshold amount of previous terminators, cycle sequenced products, etc.
after which you get a lot of unwanted junk in your 'cleaned' product. Has
anyone else experienced this? Does anyone know if there's a way to
wash/purify the columns to ensure that they're free of DNA, dNTP's, etc.?
Thanks in advance!
vrdefili at uci.edu