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What Is The Quality Assurance Of The Genetic Testing Laboratory?

Mar 04, 2019

Genes have always been an unknown world that humans have always wanted to explore. With the continuous exploration and research of the unknown world, the continuous development of science and technology, genes are becoming more and more familiar to the public. I don’t know the little friends will explain in detail in a small series. So what about the labs that study genes? Are the quality of these genetic laboratories going through? How is its quality guaranteed? Come check it out!

lab furniture 03.04

1. What is a gene?

A gene (genetic factor) is the entire nucleotide sequence required to produce a polypeptide chain or a functional RNA. Genes support the basic structure and performance of life. Stores all the information about the processes of life, blood type, gestation, growth, and apoptosis. The interdependence of environment and genetics is an important physiological process such as the reproduction of life, cell division and protein synthesis. All life phenomena such as birth, length, decline, disease, old age, and death of an organism are related to genes. It is also an intrinsic factor in determining the health of life.

Second, what is the quality of genetic testing?

(1) Quality assurance before testing:

In addition to the fact that the experimenter should be familiar with the SOP file, the environmental facilities and instrument reagents must meet the quality requirements; the molecular pathology test object is usually nucleic acid, and it is especially important to pre-process the sample, including collection, processing and preservation. If the surgical specimen is isolated from the body, it should be taken in time and fixed with 4% neutral buffered formaldehyde with a pH of 7.2-7.4. The amount of fixative is usually 10 times the volume of the specimen. The fixed time depends on the size of the specimen, generally 6-48 h. Avoiding the structural integrity or destroying tissue antigen due to insufficient or too long fixed time, resulting in unsatisfactory results of FISH and other experiments. Bone marrow and blood samples for lymphoma gene rearrangement detection must be anticoagulated with EDTA and stored at 4 °C; * The cervical exfoliated cell samples detected by the tumor virus (HPV) should be sent as soon as possible after collection. Generally, the room temperature should not be stored for more than 12 hours, stored at 4 °C for no more than 7 days, and stored at -20 °C for no more than 3 months. Another example is the RT-PCR laboratory test. The fresh tissue must be deRNase-treated or frozen in nitrogen as soon as possible to prevent RNA degradation and cause detection failure. Before the test, the information filled in the test application form must be checked carefully. After receiving the sample, it must be signed by the recipient to ensure that the number is consistent with the sample number for inspection.

(2) Quality assurance during testing:

Whether using methods published in international or national standards, or specified by authoritative technical organizations, or non-standard methods developed by their own new designs, or extended and optimized standard methods, the laboratory shall be based on the principles of the test items. The detection method is confirmed by the scope of application, sensitivity, accuracy, specificity and repeatability. The objective data is obtained by comparison with other methods, and the detection method is verified to be suitable and feasible, and the detection result is also accurate and reliable. For example, to detect tumor gene mutations with the main purpose of targeted therapy, if the conventional PCR Sanger direct sequencing method is used as the detection method of the laboratory, it can be compared with the real-time fluorescent quantitative PCR method with the same detection purpose. Information such as consistency of expected results and detection limits. Another example is the introduction of a fully automated in situ hybridization staining system for routine detection of the HER2 gene to guide clinical targeted drug therapy. For the same test items, compared to manual methods, regardless of equipment, reagents, and operating procedures. Great changes have taken place. As a new testing platform, the laboratory should develop the relevant methodological verification procedures, verify the HER2 gene test results from the aspects of equipment performance, reagent quality, and detection procedures according to the corresponding instrument operating procedures and standard operating procedures of the test items. The comparability, strengthen the laboratory indoor quality control, so that each molecular pathology test has a corresponding standard operating procedures, each instrument equipment operation, maintenance, calibration is in accordance with the prescribed procedures. Each test must be accompanied by a quality control, such as a positive control, a negative control, and so on. In addition, you should also participate in the quality comparison program between laboratories, that is, do a good job of inter-room quality evaluation, which can be by external quality assessment agencies such as the Ministry of Health Pathology Quality Control Evaluation Center, provincial and municipal clinical pathology quality control centers and clinical inspection centers. Activities planned by the organization can also be carried out by exchanging samples with other laboratories. If the quality assessment results fail to meet the control standards, the laboratory management should participate in the implementation of corrective actions in a timely manner. The laboratory shall have a record of the results of these inter-room quality evaluations and shall be documented.

(3) Quality assurance after testing:

After obtaining the test results, an authorized molecular pathologist performs an analysis review and publishes the results. Samples remaining after the experiment, such as DNA, white films, etc., can be saved as required for repeated experiments. Samples that are no longer used for testing are processed according to laboratory waste disposal procedures.

(4) Issuance of the results report:

Molecular pathologists should issue molecular pathology reports in the prescribed format within the specified time. If the test result is not obtained in time due to special circumstances and may affect the diagnosis or treatment of the patient, the doctor may be notified by postponing the report, and corrective action shall be taken in time to issue the final report as soon as possible. For the clinical significance of the test items, the evaluation principle of the test results, the precautions for the test samples, and the appropriate interpretation of the test results, patiently communicate with the doctor or patient consultation. Regularly collect the recommendations and requirements of the clinical department for the daily work and test results of the laboratory, and propose improvement measures to ensure that each workflow is within the scope of quality control.

Only by fully guaranteeing the quality of the genetic laboratory can the safety of the experimental personnel be guaranteed, and the personal safety of the experimental personnel can be fully guaranteed, thereby exploring the unknown world and better benefiting mankind.