Abstract: An implement for eliminating headspace in the testing space(s) (T9 or MPWell) of a test tube (T) or microtiter plate (MP), and methods of using such implements to measure oxygen concentration in a test sample. The implement projects into a test chamber (T9 or MPWell) to displace a portion of a fluid sample within the test chamber (T9 or MPWell) and has longitudinally extending grooves (109 and 229) through which the displaced fluidic content can be discharged from the test chamber (T9 or MPWell).

Abstract: An implement for eliminating headspace in the testing space(s) (T9 or MPWell) of a test tube (T) or microtiter plate (MP), and methods of using such implements to measure oxygen concentration in a test sample. The implement projects into a test chamber (T9 or MPWell) to displace a portion of a fluid sample within the test chamber (T9 or MPWell) and has longitudinally extending grooves (109 and 229) through which the displaced fluidic content can be discharged from the test chamber (T9 or MPWell).

Abstract: A method of maintaining an intracellular oxygen concentration of viable cells forming a cell sample at a target oxygen concentration or maintaining a micro-environmental pericellular space defined by a cell sample of viable cells at a target oxygen concentration, particularly throughout a testing period, by measuring intracellular/pericellular oxygen concentration and adjusting the concentration of oxygen in the surrounding environment in real-time based upon the measured intracellular/pericellular oxygen concentration as necessary and appropriate to influence and maintain the intracellular/pericellular oxygen concentration at a desired target oxygen concentration.