Blog - How are genetic tests done and why are they so expensive?
The cost of the analysis
The genetic analysis is carried out in several stages. Each stage involves qualified experts and the use of expensive equipment. The consumables required for the analytical machine are quite expensive, which has a significant impact on the pricing of the service. In order to get objective results, it is important to carry out an independent examination with the participation of specialists in equipment maintenance.
8 stages of genetic testing:
Stage 1. Delivery of biological material
The most commonly used type of material for further examination is blood - it contains a sufficient amount of DNA, which can be easily extracted from the sample. The biomaterial sample is taken from a vein into a test tube containing ethylenediaminetetraacetic acid (EDTA). This substance serves as a preservative, reducing the ability of the blood to clot for several days. However, it is not possible to protect DNA molecules against destruction even by EDTA, therefore, the material is transported urgently.
Stage 2. Pure DNA extraction
Along with the DNA molecules, biological material contains a considerable amount of impurities that can affect the accuracy of the analysis results. In order to prevent situations of this type, prior to further investigation the sample is cleaned by extracting pure DNA from it. Для отделения исследуемого материала образец промывают. При этом молекулы ДНК задерживаются на специальных фильтрах, потом их снимают и помещают в емкость для хранения до момента проведения исследования.
Stage 3. Quality check of the received DNA
Quality control and the amount of DNA extracted is one of the important stages of the genetic test. Extracted DNA quality and quantity control is one significant stage of the genetic testing procedure. The researched material must not contain extraneous organic substances or have traces of damage since their existence will misrepresent the results.
Stage 4. DNA amplification and fragmentation
In the Genobiosis genetic laboratory, we use microchips allowing to analyze more than 600 thousand samples of hereditary material. Before the research, it is necessary to conduct the amplification of the sample - increase in the amount of source data by copying them. For that, the polymerase enzyme is used, which is obtained from bacterial cells.
After being processed, the DNA takes the long molecule shape, thereby reducing the effectiveness of the participation of the material in subsequent processes. This problem can be solved by fragmentation of the DNA chain and special enzymes.
Stage 5. Microchip DNA Hybridization
There is a special chip that, allowing decryption of all the hereditary material that is on it. It is comprised of microscopic spheres to which the synthetic DNA fragments are applied.
A distinctive feature of artificial fragments is the ability to highlight during the study only those genetic variants that are needed for the genome determining, discarding the unnecessary information.
Stage 6. Microchip scanning
Once the hybridization process is completed, the chip is washed with solutions in different temperature conditions - this allows capturing the sample, which fragments are highlighted in different colors. The emission spectrum indicates the specificity of the researchable genome.
Considering that all these processes occur at the micro-level, for acquiring images a fluorescence microscope is used, which passes the laser rays in the chip, taking a high-resolution photo of its surface.
Stage 7. Examination of the scans and determination of nucleotides in the DNA
After scanning the chip, the data is transferred to bioengineers to extract information about the genome. They analyze the sequence of the genetic code, identify the presence of mutations and polymorphisms.
Stage 8. Interpretation of results
The results obtained during the study can be interpreted in different ways depending on the purpose of the analysis. The patient can choose a service package and receive DNA decoding, depending on the objectives set. For example, if a person wants to know whether he is at risk for oncology, he will be provided with information on tumor markers and genes responsible for a hereditary predisposition to the mentioned disease. It can be received in the Personal Account on the Genobiosis website upon processing a genetic passport.