Gelatin solution(26wt%) was mixed with GA solution (1wt%) with the gelatin/GA volume ratio 7.5/1.0 at 45 ℃ for gelation in a polypropylene tube and allowed to react for 2min. In the case of albumin gel, 45wt% albumin solution was mixed with 10wt% GA solution with the albumin/GA volume ratio 4.0/1.0. After addition of 5mLPBS(-）solution to the gel (1g) and incubation at 37℃ for predetermined durations, the supernatant(extract) was collected and the same amount of new PBS(-） was added, followed by extraction. Release of the unreacted aldehyde from the gelatin gel to each of PBS(-)was determined with the MBTH method.
我理解的是：
26wt%的明胶溶液与1wt%的戊二醛溶液按体积比7.5：:1.0在45℃条件下混合，塑料管内反应2min，制成1g胶；45wt%的牛血清白蛋白溶液与10wt%戊二醛溶液按体积比4.0:1.0按上述方法制成1g胶。
然后在塑料管内加入5mlPBS，37℃培养预定时间（如1,2,3,4,5h）后，收集上清液，用MBTH方法测量5ml上清液中未反应醛的释放量。同时再在这个塑料管内加入5mlPBS,再培养预定时间后，收集上清液，MBTH方法测量5ml上清液中未反应醛的释放量。
如果时间间隔均为1h，那个对于同1g胶来说，每个5mlPBS测得的醛含量为每1小时内的释放量，如果我想得到前2,3,4,5...小时内的醛释放量，就得把每个值相加，这样理解对吗？如果对的话，相加得到的值误差不会不太大？谢谢各位解答，不胜感激！




我个人理解是：如果你测定甲醛的量不需要5ml的话，可以1h后取1ml，然后加1mlPBS。2h后取1ml，再加1mlPBS，依次类推，可以测1.2.3.4.5h的甲醛含量。the supernatant(extract) was collected and the same amount of new PBS(-） was added, followed by extraction。这句话并没有说一次要取5ml，再加5mlPBS。




个人理解，按照“predetermined durations”的i说法，应该不会推荐累计计算的方法。因为，每次取样后补加的PBS的体积是精确的，因此是可以测定的。供参考。