Page 138 - PCC02

Ammonium
• AA present in the culture medium break down at 37˚C in a time dependant manner to release ammonium which affects cell physiology
• In embryo culture media ammonium accumulates to levels from 50μM(Gilbert 2012) to 300μM (Gardner &Lane 1993) depending on the concentration of AA and duration of culture
• Therefore even though the production of ammonium cannot be prevented some efforts can be made by modification on the culture medium composition and move to the use of reduced O2% to keep the level >75μM; the lowest concentration reported to have an adverse effect on the cleavage stage human embryo (Zander 2006, Lane & Gardner 2003)
Virant-Klun et al., F&S 2006
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