Fixation for biological ultrastructure. I. A viscometric analysis of the interaction between glutaraldehyde and bovine serum albumin.

The increase in viscosity resulting from mixing concentrated solutions of albumin with dilute glutaraldehyde has been investigated. The viscosity changes are slow at first, very sensitive to small changes in glutaraldehyde concentration, and non-linear with time. The cross-linking of the albumin by glutaraldehyde seems to be retarded by the weak mechanical shear forces produced by the viscometer. The significance of these findings to the events in tissue fixation is discussed.