We are trying to freeze-dry samples of IgG with formic acid and
pyridine using a speedvac. Most samples come out with "whitish
chunks" on the sides of the tubes that will not re-suspend in water.
However, on a couple of the samples the vacuum pump was acting up
(the pressure was very weak) and the samples dried quite nicely and
re-hydrated without a problem. Anyone have any ideas how to keep the
white stuff from precipitating before the sample is dry? Or maybe a
target pressure to run the speedvac at?
Thanks
A
