Membrane-covered thin-layer optical cell for gas-reaction studies of hemoglobin

✍ Scribed by D. Dolman; S.J. Gill

• Publisher: Elsevier Science
• Year: 1978
• Tongue: English
• Weight: 454 KB
• Volume: 87
• Category: Article
• ISSN: 0003-2697
• DOI: 10.1016/0003-2697(78)90576-6

✦ Synopsis

A thin-layer sample cell, holding between 1 and 8 ~1 of hemoglobin solution between a glass window and a transparent gas-permeable membrane, has been developed for spectroscopic studies of hemoglobin reactions with gaseous ligands. The partial pressure of reactant gases is accurately changed through a set of equally spaced logarithmical values by means of a precision dilution valve connected to the sample cell. After a partial pressure change, a new equilibrium state is reached. The time required to establish this state, usually on the order of a few minutes, is dependent upon the sample thickness, affinity, concentration, and the degree of saturation. Sample thicknesses between 0.025 and 0.15 mm have been used for studies in the visible spectral region with hemoglobin concentrations varying between 0.5 and 15 mM heme. High stability of the sample geometry is indicated by constancy within 0.001 OD of a 0.5 OD hemoglobin sample over a period of 1 hr.