Method for oxygen content and dissociation curves on microliter blood samples.

Abstract

O2 content of 7 [mu]l of blood can be determined by injecting a blood sample from a calibarated pipette into a thermostatically controlled glass chamber containing a magnetic stirring bar and a solution of ferricyanide and saponin. The O2 bound by the hemoglobin is released into physical solution and the resulting change in O2 pressure is measured with an O2 electrode. A determination can be completed every 7 min. Replicate determinations have a standard deviation of 0.14 ml O2 per 100 ml blood. The difference between 8 mean values of O2 content determined by this method and that of Van Slyke and Neill had a mean value of 0.03 ml O2 per 100 ml blood (standard error = 0.06). The method can be used with a microtonometer and gas-mixing system to construct O2 dissociation curves from 200 [mu]l of blood.