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5/22/97
A warning to researchers who are using MBCF oligonucleotides in cloning experiments.
Specifically oligos with run numbers 29,220 through 31,395.
We have just isolated a problem in the delivery of one of the two capping reagents. This reagent caps failed sequences so that no internal deletions occur. Because one of the capping reagents was intermittently delivered these products can contain internal deletions. DNA sequencing and PCR primers will not be affected as a majority of oligonucleotide product will be full length.
The problem may occur if you have used one of these oligos to construct a clone, whether by PCR or direct ligation. A minority of product in the vial may contain deletions and the clone you pick may then incorporate this deletion. If you are going to use one of these oligos for cloning please let us resynthesize it immediately.
If you have already used an oligo for cloning and suspect internal deletions please let us sequence across the site immediately.
Of course any resynthesis or sequencing will be free of charge.
Please notify us if you have had any problems so that we can isolate the problem oligos. These oligos may only be a small subset of oligos 29,220 through 31,395 and by your notification we can more clearly define suspect oligos.
Please do not hesitate to immediately bring back a synthesis that you may have a problem with. We can exonuclease digest it and mass analyze the sequence to find out if there is a problem. While we have many safeguards on the instrument the ultimate safeguard is this immediate feedback.
This notice is being sent to all DFCI e-mail addresses but please make sure that all of your lab personnel know of this notification.
addendum (6/16/97): this problem was not as bad as feared. There were some oligos that have been identified with deletions. These oligos have been identified and resynthesized.We have changed our protocols so that even this rare fluctuating valve failure will be spotted immediately and failed product will not shipped to your lab. Sincerely, Paul Morrison
