Red cell-mediated microinjection of antibodies

Macromolecules can be introduced into cultured mammalian cells by fusing recipients with red cells, loaded by hypotonic hemolysis with the macromolecule of interest. This technique is called red cell-mediated microinjection. If recipient cells are in mitosis at the time of fusion, introduced macromolecules have access to nuclear components. When antibodies are introduced by this technique, they retain their specificity and are able to neutralize both cytoplasmic and nuclear molecules, thus providing a useful system for studying cellular functions within living cells.