Figure 7.

Ultrastructural histology of microvesicles in different stainings. Positive Prussian blue reaction of the microvesicles in a WHHL rabbit with VSOP (A). In the Movat pentachrome stain, the microvesicles show a positive Alcian blue reaction indicating GAGs (B). The critical electrolyte concentration staining method at 0.4 M magnesium chloride in combination with Alcian blue according to Scott and Dorling²³ indicates the presence of highly sulfated glycosaminoglycans such as heparin, heparin sulfate, or keratan sulfate (C). The von Kossa stain reveals a staining pattern comparable to the other staining procedures (D). The Alizarin stain at pH 11 as described by Puchtler et al²⁷ results in more differentiated ultrastructural staining than the von Kossa stain (E), whereas the Alizarin S stain at pH 4.2 (F) and pH 6.4 (not shown) failed to provide useful results with regard to the differentiation of mircovesicle structures.²⁷

Abbreviations: WHHL, Watanabe heritable hyperlipidemic; VSOP, very small superparamagnetic iron oxide particles; GAGs, glycosaminoglycans.