[RASMB] more on dithionite and Hb

[John Philo]

Regarding handling oxygen-sensitive materials in the centrifuge, first I
agree fully with Jack Kornblatt's statements about dithionite and had said
something similar to Mitra privately yesterday, and recommended he try an
enzymatic oxygen scavenging recipe I used for Hb kinetics studies in the
past. 

Second, one additional point is that Todd Schuster told me years ago that
the Epon centerpieces are a significant source of oxygen. I believe the
old-timers would soak the centerpieces in dithionite solutions for several
days to deplete that oxygen and then the need for oxygen scavenging capacity
is much reduced.

John 

-----Original Message-----
From: rasmb-bounces at rasmb.bbri.org [mailto:rasmb-bounces at rasmb.bbri.org] On
Behalf Of Jack Kornblatt
Sent: Thursday, February 05, 2009 8:04 AM
To: RASMB
Subject: [RASMB] more on dithionite and Hb

Hello Mitra
Chance, I think, once described dithionite as man's worst enemy. the
concentration that you are using is far in excess of what is need to keep
your solutions anaerobic. The reaction products of dithionite are too
numerous to list even if I could remember them. If you degas your solutions
just before loading and then add dithionite to 1 mM this should give you the
desired "low" oxygen.
Is it really necessary to keep dithionite as low as possible? I have little
experience with Hb but if we use dithionite and cytochrome c oxidase at 11
mM there are sufficient biproducts generated that interpreting data is very
difficult

best
jack kornblatt
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