Purified yntatl trypanosomes were broken by n - tosyl - lysine chloromethyl ketone ( tlck ) and centrifugated by high g to form soluble proteins . the soluble proteins were chromatographed on a de - 52 column . the material in the first peak constituted the purified vsg 用国际命名法命名为yntat1 . 1 、 yntat1 . 2 、 - - - yntat1 . 20 ，从实验结果中未见这20个vats在5只兔体内按照某种特定规律变异，但是其中有15个优势vats在连续感染中多次重复，这印证了某些vats倾向于在感染早期出现的规律( gray1965等) 。
