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Reference materials are an important tool in ensuring the validity of the test results efficiently and economically. National Institute for Food Control has implemented several studies, characterization of microbiology chemistry for food and feeding stuffs certified reference materials (CRM) in order to support laboratories in control and maintaining test results quality. CRM for Escherichia coli (E. coli) in food is our study’s first interest, because E. coli indicates unfavorable hygienic conditions and fecal contamination in foods. Milk and dairy products are used for any stage of human life from infancy to elder. CRM for E. coli in milk-based products were characterized by using a network of competency laboratories leading to certified values in accordance with ISO 17034:2016 requirements. These certified reference materials produced are accredited conforming to ISO 17034:2016 by the America Association of Laboratories Association.

The research aims to determine the effectiveness of micro teaching in developing STEM teaching organizing skills for pre-service Chemistry teachers (teaching organizing skills for pre-service Chemistry teachers - TOSfPCT). This approach was evaluated through the constructivism and experiential learning theories. This research was conducted within a course for six weeks period during the 2nd semester of the 2020-21 academic year at a Chemistry faculty, Hue University of Education. The article presents the micro-teaching process combined with the application of information technology in developing STEM TOSfPCT, pre-\post-test quasi-experimental design with control group was applied. The experiment involved applying micro teaching to the experimental group (EG) while the courses were carried out using traditional lectures in the control group (CG). Mann Whitney U Test and Wilcoxon Sign Test were used in the analysis of the quantitative data. The results obtained from Mann Whitney U Test and Wilcoxon Sign Test suggest that there is no significant difference between the pre-test scores of the experimental and the control groups. Descriptive data also demonstrated that the use of the micro teaching in the curriculum had significantly increased the skill levels of the experimental group pre-service Chemistry teachers.

Polyclonal antibodies from vaccinated mammalian have made a significant contribution to scientific research and diagnosis. The fact that recent technologies allow the production of antibodies in egg yolks laid by hens has led to the development of an alternative to antibody production that is less dangerous to animals. The results of this study showed that it is possible to produce a large amount of IgY antibody to bovine serum albumin (BSA), content of about 8 mg/mL of egg yolk emulsion. The anti-BSA IgY antibodies with high purity and anti-BSA activity.

According to the General Education Curriculum 2018, natural scientific competence is a specific ability that needs to be formed and developed for students in teaching Natural Science. Understanding nature competence is one of the three components of natural scientific competence. The expression of this competence is that students can perform some basic skills to understand and explain natural phenomena, demonstrate practical problems with scientific evidence. In this article, we analyze the application of the 5E teaching model as a measure to develop students’ understanding of nature competence and illustrate the use of this model in teaching the lesson “Some Natural Materials” - Natural Science Grade 6.