Based on the current global outbreak of infectious viruses, the nucleic acid test results of the virus are currently the most important basis for judging whether people are infected with the virus. The object of nucleic acid detection is the nucleic acid of the virus. Nucleic acid testing is mainly to find out whether there is foreign virus nucleic acid in the patient's respiratory tract specimens, blood or feces to determine whether they are infected with the virus to be tested. Therefore, once the nucleic acid is "positive", it proves that the patient has been infected with the virus. In this way, it is possible to screen out virus carriers that have not developed during the incubation period to avoid uncontrollable spread of the virus. For example, COVID-19, which is raging around the world , first reproduces in the respiratory system after infecting the human body. Therefore, medical personnel can determine whether the human body is infected with the virus by detecting the viral nucleic acid in the sputum or nasopharyngeal swab. Virus nucleic acid detection only needs to detect the presence of a specific viral sequence in the sample to be tested, so whole genome sequencing is not required. The nucleic acid detection kit will make the process more convenient and faster.
Because the sequence of the virus to be detected is known and nucleic acid detection only needs to be qualitatively present or not. Therefore, there is no need to perform next-generation sequencing on the sample to be tested, and then compare whether there is a viral gene sequence. Our silicon-based high-throughput htDNA-chip® technology platform is mainly used for high-throughput amplification of DNA in nucleic acid detection. The specific process of nucleic acid detection is shown in the figure below. First, the throat swab sample is subjected to cell disruption, and the DNA of the sample to be tested is extracted. Due to the instability of RNA as viral genetic material, in order to avoid failure of the test sample, we reverse transcribed RNA into corresponding cDNA by adding reverse transcriptase. cDNA is more stable than RNA and can be used as a template for subsequent amplification. Then we can perform high-throughput amplification through htDNA-chip® technology platform. At the same time, specific primers and Taqman probes for virus sequences need to be added. Taqman probe is a specific oligonucleotide sequence with a reporter fluorophore and a quencher fluorophore labeled at both ends. When the probe is intact, the fluorescent signal emitted by the reporter group is absorbed by the quenching group. If there is a viral target sequence in the reaction system, the Taqman probe binds to the template, and then the probe will be digested and degraded. Finally, the reporter group and the quencher group separate and emit a fluorescent signal. Each time the DNA strand is amplified, a fluorescent molecule is produced. Finally, the level of the fluorescent signal can be detected to determine whether the virus to be tested is present in the sample.
Fig.1 htDNA-chip® in the process of nucleic acid amplification testing
All services are available on a 24/7/365 basis. If you are interested in CD BioSciences' htDNA-chip® platform, please contact us.