3 . peg semilethal concentration was 40 % and nacl semilethal concentration was 200 mmol / l in plbs by the detection of survival rate of plbs subjected to various concentrations 通过对不同浓度peg和nacl处理后plbs存活率的测定,得出plbs的peg半致死浓度为40 、 nacl半致死浓度为200mmol / l 。