Similarities of Giardia antigens derived from human and animal sources

A total of 37 Giardia stocks isolated from humans and 14 stocks derived from animal sources have been analysed for antigenic differences. Separation of the proteins of the stocks by polyacrylamide gel electrophoresis showed no major differences among the stocks. Immunoblotting of these antigens demonstrated some minor differences which were not correlated with geographic location, allozyme type, virulence or any other distinguishing characteristic of the stocks. Immunofluorescence tests using monoclonal antibodies revealed some differences between stocks but the monoclonal antibodies did not significantly inhibit growth in inhibition assays.