From Bioblast
Description
The standard Chamber volume of the O2k is 2.0 mL of aqueous medium with or without sample, excluding the volume of the stirrer and the volume of the capillary of the stopper. A modular extension of the O2k, the O2k-sV-Module, was specifically developed to perform high-resolution respirometry with reduced amounts of biological sample, and all components necessary for smaller operation volume of 0.5 mL.
Reference: MiPNet22.11 O2k-FluoRespirometer manual
MitoPedia O2k and high-resolution respirometry:
DatLab