Enumeration of alphafetoprotein secreting cells using a reverse hemolytic plaque assay during the growth of Morris hepatoma 7777 in culture.

Enumeration of alphafetoprotein (AFP) secreting cells in subcultures of rat hepatoma McA-RH7777 has been achieved by a reverse hemolytic plaque assay. The proportion of the cell population engaged in AFP production varies during the growth. Its maximum is reached during the late exponential phase and precedes the maximum of daily AFP accumulation in the culture medium. Then the proportion of AFP secreting cells decreases whereas AFP accumulation remains high, suggesting a change in AFP secretion rate.