How is paternity tested?
Paternity testing is a technical means to determine whether there is a biological relationship by analyzing the DNA of parents and children. Below, we will introduce the method and process of paternity testing in detail.
Step one: collect samples
Paternity testing requires the collection of samples for testing. Generally, the samples collected include blood, oral mucosa, hair, nails, etc. The process of collecting hair and nails is simple and non-invasive. The collection of oral mucosa requires professional technicians, and blood collection needs to be done in Conducted in a hospital or laboratory.
Blood collection process:
Collecting high-quality blood samples generally requires the following steps:
The first step is to choose a suitable blood collection point. Blood is generally collected from the anterior cubital fossa vein or the dorsal hand vein.
In the second step, before blood collection, you need to prepare tools and clean the blood collection site, such as cleaning the skin, puncturing, inserting the blood collection needle, and ensuring the safety of the blood sample through a stapler and a transparent sealing bag.
In the third step, after blood collection is completed, anticoagulant needs to be added and centrifuged in a centrifuge to eliminate confusion between blood cells and plasma.
Step 2: Extract DNA
Extracting DNA is an important step in paternity testing. DNA extraction can be carried out using many different methods such as chemical methods and automatic extraction instruments. Chemical methods have a wide range of applications and are relatively low-cost. They also require high extraction purity and a large enough sample size.
Chemical extraction of DNA:
The first step is to add easy incubation solution to break the cell wall.
In the second step, protease is added to digest the proteins outside the nucleus.
The third step is to add a filter layer to filter out adhesive proteins and small fragments of nucleic acids.
The fourth step is to add phenol chloroform. Phenol has the advantage of isolating nucleic acids.
The fifth step is to centrifuge the sample, with the phenol hydrophilic layer on top, and add isopropyl alcohol to obtain the nucleic acid sample.
Step 3: Amplify DNA
Amplifying DNA is a crucial step in paternity testing. PCR is currently the most common and efficient DNA amplification technology. It introduces some specific primers to specific DNA sites in the sample to generate a large amount of template DNA for amplification. DNA fragments amplified by PCR can be used for detection and identification.
PCR technology amplifies DNA:
In the first step, specific enzymes are used to cut the DNA to the appropriate length.
In the second step, DNA polymerase and enough specific primers are added to produce a large amount of template DNA.
In the third step, within a certain period of time, the large amount of template DNA produced is combined with methylated fluorescein through free complementary groups to obtain amplification products.
Step 4: Compare data
In the process of comparing data, the sample being tested is compared to the DNA sequence in samples from parents or other relatives. The comparison results need to be analyzed and judged through certain algorithms and judgment standards to obtain the results of the parent-child relationship.
Data analysis:
By detecting, extracting and amplifying DNA, aGroup DNA sequence data needs to be compared using computer analysis tools and to determine the results of paternity testing. When performing data analysis, various errors generated during sample extraction and amplification need to be taken into consideration, and patient confidentiality and privacy also need to be properly protected.
Conclusion
Paternity testing is a very effective technology that scientifically analyzes the DNA sequences between parents and children to confirm or exclude the existence of a parent-child relationship. However, in actual operation, technical means such as sample collection, DNA extraction, amplification, and data processing need to be reasonably selected to ensure the accuracy and reliability of paternity test results.
