Restrictions on Antibody Production by Single Cells

Although a cell normally produces an antibody specific to a single determinant only, this does not imply that, had circumstances been different, such a cell could not have produced a different antibody; mechanisms have been postulated (e.g., Szilard, 1960) by which a cell could be ‘locked’ in specific production once it had started. Since a cell cannot be persuaded to retrace its history and start again, an alternative approach is to see whether there are other restrictions on the products of an individual cell which may affect the kind of antibody which it can produce: restrictions for instance upon the kind of IgG which it can synthesize, apart from the specification of the antibody combining site.