A rapid method for obtaining the half saturation tension of small blood samples using a standard Clark electrode...

A method is described which allows the half saturation tension (T50 value) of blood to be obtained within 5 min on samples of 100 mul volume, using a standard Clark PO2 electrode A PO2-time trace is recorded on a blood/buffer suspension from which the oxygen is removed at a constant rate using yeast cells. The T50 value is then derived graphically. The values taken for 210 traces show the graphical solutions to lie within +/- 0.5 mmHg of the tensions calculated from complete dissociation curves. Values from a further 590 traces show the T50 estimates are also reproducible with a standard error of less than 0.3 mmHg.