Common Solutions and Reagents
Bicarbonate-Buffered Physiological Saline Solutions (PSS)
For most experimental applications, the use of a bicarbonate-buffered PSS is preferable. Bicarbonate-buffered saline solutions require aeration with carbon dioxide/oxygen mixtures to achieve proper pH control. Common gas mixtures for aeration of bicarbonate-buffered PSS are 95% O2, 5% CO2 and 20% O2, 5% CO2, balance of N2.
- Standard PSS – Used in general purpose applications
- High K+ PSS (60 mM K+) – Used to induce vasoconstriction via K+-induced depolarization
- Standard Artificial Cerebrospinal Fluid (ACSF) Solution – Used in studies involving isolated cerebral vasculature
HEPES-Buffered PSSs are used in applications when aeration with oxygen/carbon dioxide is not feasible. The most common scenario is an experiment in which the bathing media cannot be superfused, but must remain stagnant in the tissue bath. This situation is most often brought about by the need to minimize usage of expensive drugs, peptides, or other reagents.