Anyone who has done phosphorescence work with proteins understands the
importance and difficulty of removing oxygen from samples and subsequently
keeping it removed. Our deoxygenation apparatus consists of a cylinder of
argon gas connected to a regulator which is then connected to an oxygen
removing filter. After that, the argon gas is sent into a three-way
solenoid valve which connects to our sample cuvette and then to either an
open vent or a vacuum pump. Our current procedure cycles the exposure of
our sample to argon for 1 second and then to the vent (or vacuum) or 0.1
seconds. We usually let our samples cycle for about 1 to 1.5 hours to
ensure complete deoxygenation.
Our cuvettes are made by the University of Michigan Glassblowing Shop and
consists of fused cylindrical quartz tubing (10 mm tubing fused to 6 mm
tubing). The 10 mm tubing end has a flat bottom and the 6 mm tubing end is
open. This cuvette is attached to a quick disconnect valve using an Cajon
Ultra-Torr® seal. We have tested the
system and have determined that it maintains its seal over days, even at
high ( > 60 degrees C.) temperatures. The relatively low cost, ease
of use and general robustness of this this system make it invaluable for
deoxygenation and phosphorescence research.
