Kit for extracting DNA of cast-off cells in human excrement sample and extraction method

Abstract

The invention provides a kit for extracting DNA of cast-off cells in a human excrement sample. The kit is characterized by comprising the following reagents: 1) a sample preservation buffer SPB; 2) acell capture buffer CCB; 3) a cell lysis buffer I; 4) a DNA extracting solution I; 5) DNA dissolving liquid EB; and 6) absolute ethyl alcohol and 75% of ethanol. The invention further provides a method for extracting the DNA of the cast-off cells in the human excrement sample by using the kit. The kit and the method disclosed by the invention have the advantages and application values: 1, the sample is simple and convenient to collect, noninvasive and personalized and convenient, a specially-assigned person is not needed for assisting in sampling, and automated sampling can be performed; the excrement sample is simply sampled (the excrement sample does not need to be collected at a specified position with necessary requirement, and the formed excrement sample can be randomly collected), the sample can be collected by a sampler in person, the sampler does not need to be assisted in sampling by a professional in a hospital, and the operation is convenient, non-intrusive and friendly to experience of the sampler; 2, the sample is conveniently preserved and can be placed at a normal temperature; and 3, sample pretreatment is simple, and treatments such as centrifugal elutriation, density gradient centrifugation, magnetic activated cell sorting and the like are not needed.

Description

technical field [0001] The invention relates to a method for extracting nucleic acid (DNA) in the field of medical biology, in particular to a method and application for extracting exfoliated cell DNA from human feces. Background technique [0002] Feces are food that is chewed through the mouth, reaches the stomach through the esophagus, is digested by the stomach, enters the duodenum, and is digested and absorbed by the small intestine under the joint action of bile and pancreatic juice, and finally forms the residue excretion in the large intestine. Feces are the final metabolites to keep the internal environment of the body stable. In addition to water, protein, inorganic substances, fat, and undigested dietary fiber, it also contains bacterial cells, viruses, and exfoliated cells of the epidermis of organs. The bacteria in the feces mainly come from the intestinal flora or a small amount from the food; the exfoliated cells of the epidermis of the organs mainly come from...

AI Technical Summary

Problems solved by technology

However, such a sample loading method not only requires a large amount of extraction reagents for feces sample liquids with low nucleic acid content and large sample volume, but also takes too long to centrifuge, which is not conducive to the extraction of nucleic acids.

In view of this problem, although many studies have proposed corresponding solutions in recent years, such as centrifugal elutriation, density gradient centrifugation, and immunomagnetic bead method, these research methods have strict requirements for stool sampling, high requirements for stool sample preservation, and high requirements for consumables and equipment. The defects of high equipment requirements, cumbersome and time-consuming operation procedures, etc. In addition, some fecal DNA extraction kits on the market not only cannot completely solve these problems, but also the actual quality of the final extracted DNA cannot meet the official public indicators, and the price is also low. Relatively expensive, difficult to realize the application in molecular detection

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