Immunogold labelling is a quantitative method as demonstrated by studies on aminopeptidase N in microvillar membrane vesicles.
Microvillar membrane vesicle preparations with varying content of aminopeptidase N were prepared from enterocytes of the pig small intestine. Postembedding immunogold labelling of aminopeptidase N was performed on these glutaraldehyde/paraformaldehyde-fixed, osmium tetroxide-treated and Epon-embedded microvillar membrane vesicles. The number of gold particles per micrometre microvillar membrane (labelling intensity) was calculated and compared to the corresponding enzymatic activity. A very close relationship was found between labelling intensity and aminopeptidase N activity, demonstrating that postembedding immunogold labelling can be used quantitatively.
Department of Biochemistry C, Panum Institute, University of Copenhagen, Denmark.
G H
GH
Hansen
L L
LL
Wetterberg
H
H
Sjöström
O
O
Norén
D000626:Aminopeptidases / Q000032:analysis*; D000818:Animals; D018826:CD13 Antigens; D007150:Immunohistochemistry; D007421:Intestine, Small / Q000201:enzymology* / Q000648:ultrastructure; D008871:Microvilli / Q000201:enzymology; D010206:Papain; D013347:Subcellular Fractions / Q000201:enzymology; D013552:Swine
D000626:Aminopeptidases; D018826:CD13 Antigens; D010206:Papain