Formation of nuclei during delay time prior to aggregation of deoxyhemoglobin S in concentrated phosphate buffer

The delay time prior to aggregation of deoxyhemoglobin S was found to be shortened significantly if monomeric deoxyhemoglobin S was added near the end of the expected delay time. This suggests the formation of a preaggregation complex of deoxyhemoglobin S, probably so-called "nuclei", near the end of the delay time. In fact, the molecular weight of deoxyhemoglobin S as measured by a low angle laser light scattering photometer increased exponentially during the delay time prior to the visible aggregation of deoxyhemoglobin S. These results support the nucleation-controlled aggregation mechanism for the aggregation of deoxyhemoglobin S in concentrated phosphate buffer.