Attaching Suspension Cells to Slides for Staining

Suspension cells can be prepared for staining by several different methods. A simple method for detecting intracellular antigens in cells that grow in suspension is to attach the cells to a solid substrate before fixation. This can be achieved by the use of a cytocentrifuge. For surface staining, suspension cells can be attached to slides by cross-linking with poly-l-lysine. Lysine can be polymerized to any desired length, and poly-l-lysine will bind to most solid supports through its charged side chains. The positively charged polymer will provide a site for binding of cells (which carry an overall negative charge). Although this cross-link is not covalent, it is sufficiently strong for most cell-staining techniques.