Detection of human white cell proliferative responses by immunoenzymatic measurement of bromodeoxyuridine uptake.

The proliferative response of human white cells to stimuli such as foreign histocompatibility antigens or mitogens is traditionally assessed by measuring the amount of [3H]thymidine which the cells can incorporate in culture. In the present paper a new approach is described in which bromodeoxyuridine (BrdUrd) is used in place of thymidine and measurement of incorporation of this molecule is performed by an immunoenzymatic assay (using monoclonal anti-BrdUrd). The procedure avoids the expense, time and hazards associated with scintillation counting, and is simpler to perform. It also appears to be particularly sensitive to low levels of proliferation, and may thus detect such responses more effectively than thymidine incorporation.