Official website of Nanjing Jiantong shows that the total cost of personal paternity test is 2,400 yuan, and the total cost of judicial test is 3,000 yuan. For reference. Online reputation is not bad. If only personal paternity test can be considered, anonymous identification can be conducted without providing identity documents. Nanjing Jiantong belongs to the postgraduate workstation of Nanjing Medical University, and paternity test is only a part of their business. Online reputation is not bad, and anonymous paternity test can be accepted. Samples that can be used for personal paternity testing include routine samples and special samples, where the routine samples include blood stains, hair with hair follicles and oral cotton swabs; Special samples are semen stains, cigarette butts, toothbrushes, chewing gum, etc.

All nucleated cells in the human body can be used for DNA identification, usually oral examination, blood stains, hair with hair follicles and so on. And adult men can also be semen spots.

Precautions for sample collection and mailing:

It is generally required to collect a drop of fingertip blood at the scene. If there are special circumstances, you can collect them yourself.

Collect more than three drops of blood from fingertips or earlobes in hospitals or at home, and put them on clean gauze or cotton balls to dry naturally.

Hair submitted for inspection must have hair follicles, that is, plucking (more than five hairs). Send it within five days or freeze it for inspection.

Amniotic fluid tissue should be frozen.

Blood stains, seminal spots and mixed spots, saliva, cigarette butts, chewing gum and other samples should be naturally dried, sealed with packaging bags or stored in the refrigerator at -20℃.

Mailed samples should be packaged and labeled, and samples used for pathological identification should indicate the relationship between father, mother and son.

Experimental steps of DNA identification:

Step 1: DNA extraction

The DNA contained in the sample nucleus is extracted and then purified to remove impurities in the sample.

Step 2: PCR amplification

The Chinese name of PRC is polymerase chain reaction. Simply put, the step of PCR diffusion is to amplify the fragments we need to the extent that some special instruments can see them through enzymatic reaction.

Step 3: Post-PCR reaction

This step is mainly the preparation stage of sequencing instrument detection, which opens the double-stranded DNA and adds some internal standards for detection, mainly marking the length of the detection fragment.

Step 4: Capillary sequencer detection.

Because DNA is charged, capillary electrophoresis has different electrophoresis speeds for different fragments of DNA. Under the same voltage and electrophoresis time, the swimming distance is different. These different distances can be distinguished by the internal standard measurement added in the early stage, and displayed on the computer through certain software, which is convenient for inspectors to process and analyze the data.

Step 5: Analyze the data and issue a report.

It is mainly for inspectors to analyze, summarize and calculate the obtained results, and then make appraisal conclusions and reports.