A thin-layer optical cell for spectroscopic studies of oxygen binding to hemoglobin

A thin-layer sample cell for examination of the spectra of hemoglobin at various degrees of gaseous-ligand saturation has been constructed to fit into a Cary 17 spectrophotometer. Small sample volumes of 50 μl are used. Equilibration times of only a few minutes are required between taking spectra at different degrees of saturation. Apparatus stability is high as revealed by reproducibility and isosbestic point behavior. Incorporation of an oxygen electrode enables simultaneous measurement of oxygen partial pressure for intermediate spectra.