Polyaldehyde microspheres as probes for cell membranes

Poly(glutaraldehyde) (PGL) and poly(acrolein) (PA) microspheres in various sizes were synthesized. Addition of fluorochromes or magnetic particles during the synthesis resulted in the formation of fluorescent or magnetic microspheres, respectively. The microspheres were designed to be hydrophilic and negatively charged. They also possess reactive aldehyde groups through which various ligands containing primary amino groups were bound covalently at physiological pH. The microspheres may be used as a simple tooi for mapping cell surface receptors and for cell separation. The feasibility of specific labeling of human red blood cells (RBC), human lymphocytes, and rat basophilic leukemia cells and of the separation of human RBC from turkey RBC by means of magnetic microspheres is discussed.