Demonstration of lag phase in the sol-gel transformation of deoxygenated S hemoglobin without temperature alteration.

1). During the sol to gel transformation of deoxygenated sickle hemoglobin, a time-dependent process preceding gel formation (lag phase) was demonstrated that was inversely proportional to a function of the hemoglobin concentration and that occurred without alteration in temperature, pH, or oxygen tension. 2). As determined by the Schachman modification of the capillary viscometer, preparations of oxyhemoglobin S and A and deoxyhemoglobin A were indistinguishable when compared over a wide range of concentrations. Up to the concentration at which gelling occurred, deoxyhemoglobin S exhibited the same viscosity behavior. The viscosity of deoxygenated hemoglobin S within the lower gelling concentration range was normal during the lag phase and became abnormally high only at the time of gelation.