A "three-in-one" sample preparation method for simultaneous determination of B-group water-soluble vitamins in infant formula using VitaFast(®) kits.

VitaFast(®) test kits designed for the microbiological assay in microtiter plate format can be applied to quantitative determination of B-group water-soluble vitamins such as vitamin B12, folic acid and biotin, et al. Compared to traditional microbiological methods, VitaFast(®) kits significantly reduce sample processing time and provide greater reliability, higher productivity and better accuracy. Recently, simultaneous determination of vitamin B12, folic acid and biotin in one sample is urgently required when evaluating the quality of infant formulae in our practical work.

[Bacillus thuringiensis helper protein P20 affects the formation of Cry1Ab].

The Cry1Ab differs most significantly from the other related ICPs by its absence of a carboxyl terminus of 28 amino acids including four cysteines; consequently it is less stable. We report that the helper protein P20 plays a role in the expression and crystallization of Cry1Ab. Three Cry1Ab expression plasmids pT1B, pP1B, and pDP1B, were constructed based on the shuttle vector pHT3101.

[Cloning and expression product of vip3A gene from Bacillus thuringiensis and analysis of inseceicidal activity].

The vip3 A gene in a size of 2.3 kb amplified from wild-type Bacillus thuringiensis strain S184 by PCR was cloned into pGEM-T Easy vector and its sequence was analysized by DNASTAR. The plasmid pOTP was constructed by inserting vip3A-S184 gene into the expression vector pQE30 and then was transformed into E.