Human pancreatic B cells in vitro: microtubule and insulin immunofluorescence.

Primary monolayer cultures of human B cells established using collagenase digestion, assume a characteristic epithelial morphology which is ideal for indirect immunofluorescence studies. Using double label indirect immunofluorescence, it was possible to identify an extensive cytoplasmic microtubule complex and numerous insulin antigen positive granules within the human B cells. The microtubules are discrete rod-like structures which terminate at, or near, the plasma membrane and are observed sometimes in close association with insulin antigen positive granules. This culture system is well-suited for studying the role of the microtubules in human B cell function.