Assay of inert gas contamination in studies of hydrostatic pressure effects

In hyperbaric tissue studies it is common to use gas pressure as a means for increasing the hydrostatic pressure of the preparation. When this is done, one must take the necessary precautions to avoid gas contamination of the tissue. In the present study, we demonstrate a) methods for calculating the gas contamination using particular materials in the perfusion system, and b) a technique for isolating the fluid environment from contamination by the compressing gas in a flow-through tissue chamber. The present work is exemplified with a specific apparatus, but the general principle is applicable to other studies.