FIG. 2.

Samples were loaded onto a 4 to 12% SDS-polyacrylamide gel electrophoresis gel, electrophoresed, and transferred to nitrocellulose. Lane 1, 20 μg human conjunctival homogenate; lane 2, 20 ng human lacrimal gland homogenate; lanes 3 to 5, 20 nl human tears from three healthy adults. gp340 was detected using a specific antiserum. gp340 is present as a dispersed high-molecular-mass band in these samples. Tissue-derived gp340 is of lower molecular mass than the secreted form, probably due to incomplete glycosylation of the immature glycoprotein. The arrow indicates migration of a 250-kDa molecular mass marker.