An investigation into the use of protein cross-linking agents as cell fixatives for confocal microscopy.

A variety of compounds which are known to cross-link proteins have been tested as possible cell fixatives for confocal microscopy. The criteria for good fixation that were used for this work were that the fixative should make the cells resistant to lysis and the loss of protein from the cell under hypotonic conditions. In addition, fixation should not change the shape nor the volume of the cell. Of the compounds tested, one compound, EDC, appeared to have an excellent potential as a cell fixative and has the additional advantage that it does not require amino groups for its crosslinking activity. Another compound, SPDP, appeared to have some potential as a readily reversible fixative by virtue of its disulfide bridge.