STR cell identification significance

Guide:

Are the newly purchased cells, the cells that have been passed down for generations in the laboratory, or the cells that have been stored in the ultra-low temperature refrigerator for several years, are contaminated? Is the identification correct? Does research with it affect the results of the experiment? Without the corresponding cell identification, the contaminated cells were used, and after a large number of experiments, a paper was written, but the conclusion was overthrown, the paper was recalled, a lot of time, material and manpower was wasted, and everything had to start all over again.

Background introduction

The problem of misidentification and cross-contamination of mammalian cells used in biomedical research has been a widespread problem. According to statistics, about 20% of cell lines in foreign laboratories have been misidentified and cross-contaminated. NIH and ATCC have called for this in the past two years, requiring researchers to identify cells. In recent years, a large number of studies have shown that the STR genotyping method is one of the most effective and accurate methods for cell cross-contamination and characterization. The application of STR genotyping to cell identification has been strongly recommended by institutions such as ATCC.

The necessity of cell STR identification

The past 45 human papillomavirus (Human Papillomavirus 18 or HPV18) has been transformed into cancer cells and is quite different from normal cervical cells. It is estimated that nearly 20% of the cells in foreign laboratories have the above problems.

In 2008, three of the molecular biologist Winand13 esophageal adenocarcinoma cell lines at the Nefkens Institute in Josephine were contaminated with SEG-1, BIC-1 and SK-GT-5. These cells were mixed with other cancers. cell. These cell lines have been used in two clinical trials in several laboratories and published more than 100 SCI articles and applied for 11 US patents. The results of this study were published in the latest issue of the Journal of the National Cancer Institute. (JNCI).

In 2007, the NIH issued a notice strongly recommending the authentication when using cultured cells. At the end of 2008, experts proposed that ATCC work on the identification of human cell lines and develop standard procedures for identification.

In recent years, a large number of studies have shown that STR genotyping is one of the most effective and accurate methods for cell cross-contamination and characterization. STR genotyping for cell identification has been strongly recommended by institutions such as ATCC. The ATCC cell bank in the United States, the DSMZ cell bank in Germany, and the JCRB cell bank in Japan provide data for comparison of STR typing for each cell line.

In early 2011, the American Type Culture Collection (ATCC) developed the STR identification standard for human cell lines to limit the expansion of invalid scientific data due to cell cross-contamination and misidentification. More importantly, the precise identification of cell lines plays a crucial role in the development of cell-based medical products that avoid the risk of exposing human cells to misidentified cells.

Cell STR identification method

It is required to provide general and specific biological traits of the cells. General characteristics include: general morphology, specific structure, cell growth curve and division index, doubling time, vaccination rate, chromosome analysis, isozyme examination, DNA fingerprinting, etc. Specificity indicators are often identified based on the specificity of the cell type and function. For example, if it is a glandular cell, it is generally identified whether there are special products including secreted proteins or hormones. If it is a tumor cell, it should also be able to prove that the cell is indeed derived from tumor tissue. Rather than others, and still retain the characteristics of tumor tissue, it is often necessary to do colony formation experiments, nude mice tumorigenic experiments and invasion experiments on normal tissues.

I. Identification of normal cell lines

The identification of normal cell lines mainly focuses on the following four aspects: (1) Identification of the germline sources of cells: Common methods include chromosome analysis, isozyme analysis, DNA fingerprinting and other techniques. (2) Identification of tissue sources of cells: Identification by morphological means, detection of tissue-specific antigens, and the like. (3) Whether the cells undergo transformation and malignant transformation: mainly identified by karyotype analysis, cell growth behavior observation (whether loss of contact inhibition), nude mice tumor formation experiment, and the like. (4) Whether the cells are cross-contaminated or not, mainly identified by isozyme and DNA fingerprinting techniques.

Second, the identification of tumor cell lines

The identification of tumor cell lines mainly focuses on its malignant development, chromosome abnormalities, contact inhibition and density-dependent growth characteristics, colony forming ability, tumor formation in nude mice, invasion and growth in animals, and certain gene and molecular levels. The characteristics are the direction of tumor cell identification.

Significance of cell STR identification

Since cell culture systems are very important in the research and development of biopharmaceuticals, the proper cell line identification process has become the most interesting point for each researcher. However, the problem of cross-contamination still exists. As the number and frequency of new cell lines used in laboratories around the world increase, the fundamental principles of quality control (eg, cell line identification) vary greatly. From published research papers that have led to suspicious results using "wrong" cell lines, to stem cell lines and other cell lines used in clinical practice, cross-contamination affects every area of ​​scientific research - from lab bench to clinical. If major changes are not made in the handling and handling of cell culture, cross-contamination will become a bigger and more serious problem.

Cell culture systems are very important in the development of biological research and drug research. With the deepening of research, the types of cell lines are gradually increasing, and cross-contamination of cell lines still exists. Cross-contamination has brought serious problems to experimental research. If the wrong cell line is used to question the results of the research, the previous experiments may have to be done again. Therefore, certification of cell lines is necessary.

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