Df. Wilson et al., ANTIGEN RETRIEVAL FOR ELECTRON-MICROSCOPY USING A MICROWAVE TECHNIQUEFOR EPITHELIAL AND BASAL LAMINA ANTIGENS, Applied immunohistochemistry, 4(1), 1996, pp. 66-71
The current study extends the principles of the antigen retrieval tech
nique for formalin-fixed, paraffin-embedded tissues to transmission el
ectron microscopy. Specimens prepared for both routine and immunoultra
structural studies were examined for the effects of microwave treatmen
t on the immunolabeling of tissue antigens. Specimens of normal rat to
ngue mucosa and human oral mucosa were microwaved before immunogold la
beling was done using six types of antibody (types I, III, IV, and VI
collagen, laminin, and cytokeratin). Sections were cut from tissue blo
cks that had been fixed and embedded for either ultrastructural immuno
cytochemistry in L.R. White resin or routine electron microscopic morp
hology in TAAB resin. Compared with nonmicrowaved sections, microwave-
treated, immunolabeled sections of both types of embedded tissues reve
aled markedly enhanced gold labeling for type IV collagen in the oral
epithelial basal lamina. Moreover, microwave-treated L.R. White sectio
ns showed greater label density for type III and VI collagens and for
cytokeratin compared with nonmicrowaved sections. There was variable g
old labeling for laminin in both TAAB and L.R. White sections with or
without microwave pretreatment and no improvement in type I collagen d
etection in microwave-treated sections. We concluded that postembeddin
g microwave treatment of plastic ultrathin sections on sodium citrate
buffer enhances some tissue antigens by increasing the likelihood of r
eexposing epitopes encrypted by a fixative-denaturative milieu. This m
icrowave technique offers the potential of combining immunocytochemist
ry with enhanced exposure of antigenic markers of ultrastructural morp
hology in a number of extracellular sites.