Freeze-fracture and scanning electron microscopy of lymphocytes: effect of different preparatory techniques on cell surface morphology.

Scanning electron microscopy (SEM) of human peripheral blood lymphocytes (hPBL) processed by two different methods reveals the existence of two main types of cell: villous and smooth. Freeze-fracture of hPBL, also processed by two methods confirms the existence of these morphological types of lymphocyte. Moreover, although the stereo surface replica technique is not a suitable method for the study of hPBL surface due to the lability of the lymphocyte replicas, some smooth cells were also encountered. Qualitative and quantitative analysis of the number, size, length and distribution of microvilli show that variations in the experimental conditions for SEM affect the surface topography of hPBL, indicating the need for studies on the effects of methods of cell collection, fixation and dehydration on the surface morphology of lymphocytes.