PH and Temperature

Most cells grow best at a pH between 6.8 to 7.6, and the pH of most commercial media is 7.2 to 7.4. Media based on Earl's salt composition are buffered by bicarbonate/carbonic acid, and the pH is regulated by constant CO2 delivery in an incubator [11, 27]. After 30 min at atmospheric pressure, the pH rises by about 0.1 to 0.2 pH units; after 4 h, the pH is raised by about 0.3 to 0.5 pH units. Media with Hank's salt composition are buffered by phosphoric acid and should be used at normal atmosphere. The addition of 10-20 mM HEPES to the media with a good buffering capacity between pH 7.2 and 7.4 helps to keep the pH constant.

Depending upon the available instruments, screen conditions minimizing pH variations must be selected.

The ideal temperature for mammalian cells is between 36 and 37.5 °C. Short periods at room temperature are usually not critical, but the functional activity of channels [28] and the metabolic activity of the cell can be changed under these conditions.

0 0

Post a comment