Nadine-
We use the hydrolysis vials and Mininert valve caps used in the Picotag system, but have set up a very effective manual system for evacuation of the tubes and refilling with argon. All it takes is some vacuum tubing, a three-way valve, a vacuum pump, a pressure gauge, an argon tank and a safe place to put the hydrolysis vial during evacuation (we use the chamber of a vacuum centrifuge). You just have to make sure the tubing fits well beyond the threads on the valve cap. We've learned from experience about how long and at what pressure we should evacuate, how many times we should evacuate and fill with the argon.
After the last argon refill, we close the cap valve, disconnect the hydrolysis vail and put it in a forced-air oven at the desire temperature.
Right now, it's convenient enough that I'm not sure I'd go back to a Picotag work station.
Vernon
Vernon A. Shoup
Regeneron Pharmaceuticals
Rensselaer, NY 12033
(518)488-6012
vernon.shoup@regpha.com
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Date: 8/27/98 7:28 PM
From: Ritter,Nadine
The question I now have is this: If the Pico-Tag workstation is no longer
going to be available, what alternatives are there for convenient hydrolysis
methods, and how do they compare to the PicoTag system? I recall some
discussion a long while back on microwave units, but what about other methods
of hydrolysis? In reviewing the past ABRF AAA studies, two addressed
hydrolysis: in 1989, the ABRF study showed that hydrolysis was a highly
variable step in amino acid analysis, but it did not focus on the relative
merits of different hydrolysis methods. The 1994 study confirmed that good
hydrolysis is critical in obtaining accurate AA results, regardless of the
derivatization method or instrument used. Of course, hydrolysis has been an
internal part of the AAA Research Committee studies all along, but as far as
I can tell, it has never been singled out for comparative evaluation.