PH DRIFT OF PHYSIOLOGICAL BUFFERS AND CULTURE MEDIA USED FOR CELL INCUBATION DURING IN-VITRO STUDIES

In pharmacological or toxicological studies performed at room atmosphe re comparison of various media used for cell incubation revealed discr epancies among results due to pH instability when these media contain bicarbonate. With the classically used protocols, a relatively fast an d notable rise of the pH of such media has been observed, and values h igher than 8.5 could be reached after 1 h of incubation. A less import ant rise in pH was also observed for media containing low amounts of s odium bicarbonate, e.g., Hank's formula-derived media. Because Hepes-b uffered media or media with abnormal osmolarity cannot always be used for such studies, our choice of media is limited. (C) 1998 Elsevier Sc ience Inc.