be tested by western blotting by immune precipitation analysis or by fluorescent antibody techniques using antibodies specific for the htlv iii glycoproteins for western blotting analysis the unlabeled cells are extracted with a detergent containing buffer and the proteins are separated on a polyacrylamide gel after electrophoretic transfer to nitrocellulose paper the individual viral glycoproteins are detected by autoradiography using the appropriate antibody and 125 i labeled protein a as described in j biol chem 258 11219 11228 1983 hereby incorporated by reference for immune precipitation analysis cells are labeled 2 hr with 35 s methionine 50 mci ml and extracted with detergent containing buffer the radiolabeled viral glycoproteins are identified in the extract by standard immune precipitation techniques using antibodies specific for these proteins the proteins are separated by polyacrylamide gel electrophoresis and visualized by autoradiography of the dried gel as detailed in the above publication to detect the viral glycoproteins on the surface of the infected cells such as h9 cells antibodies specific for envelope protein mainly gp120 determinants exposed on the surface of the intact htlv iii infected cell are employed viable cells are reacted first with the anti envelope protein antibody followed by a second fluorescent labeled antibody that will react with the first unlabeled antibody details of the technique are described in cell 39 327 337 1984 hereby incorporated by reference expression and quantitation of the amount of vital glycoprotein fluorescein labeled on the cell surface is determined by fluorescence activated cell sorting facs an alteration in the size of the vital glycoproteins detected by western blotting and or immune precipitation indicates that castanospermine interrupts the normal carbohydrate processing of the htlv iii vital glycoproteins presumably in the.