“…In some cases vacuoles occupied most of the cytoplasmic space and contained amorphous material and membranous structures in a relatively electron-transparent medium. Much data originating from SEM studies have been interestingly controversial and advantageously contributive because of modifications of human leucocyte surface morphology caused by the variations in the techniques used to prepare these cells for electron microscopy observation (Abugaber et al, 1981;Barber & Burkholder, 1975;Corvellec et al, 1983;Lalague et al, 1982;Polliack, 1977Polliack, , 1978Polliack, , 1979Renau-Piqueras et al, 1980;Roath et al, 1978), yet very few reports on the effects of preparatory conditions on the ultrastructure of peripheral blood leucocytes have been available. We have investigated the use of (i) 4% glutaraldehyde (G)+ RpMI-1640 medium, (ii) 4% G+RPMI-1640+0.05 mol sucrose, (iii) 4% G+Hanks, (iv) L4 % G + Hanks + 0.04 ,moll sucrose, (v)] 4%dG + PBS] (phosphate ,buffered saline), (vi) light- Fig* 3.…”