Abstract: A blade platform, comprising a pair of side edges and a pair of bottom edges, wherein the side edge comprises a linear portion and a curved portion, wherein the linear portion comprises a first linear portion and a second linear portion, and the curved portion comprises a first curved portion and a second curved portion; wherein the first linear portion and the second linear portion are connected to two ends of the curved portion and are tangent to the curved portion, slopes of the first curved portion and the second curved portion are in the same direction and the first curved portion and the second curved portion are circumscribed. The benefits of the blade platform are that the problems of platforms pushing against each other and get stuck during the working state as in the prior art or lack of accuracy in the test results of the blade circumferential clearance test and the dynamic balance test can be avoided.

Abstract: The present invention relates, in general, to human immunodeficiency virus (HIV) and, in particular, to HIV-I envelope (Env) immunogens.