Legal analysis: the judicial paternity test is completely open. The single parent test must be conducted with the consent of the client's father and children (for the parent test, the client's father, mother and children agree), face to face and present at the same time, and carry relevant valid documents including ID card, household registration book, etc. And the staff of the appraisal center will take samples on the spot, and the lawyers of the appraisal center will testify and issue certificates on the spot. The appraisal results can be used for judicial purposes and can also be used as evidence in court.

Legal basis: Criminal Procedure Law of People's Republic of China (PRC).

Article 146 In order to find out the facts of a case, when it is necessary to solve specialized problems in the case, a person with specialized knowledge shall be appointed to make an appraisal.

Article 147 After conducting an appraisal, an appraiser shall write an appraisal opinion and sign it. If an appraiser intentionally makes a false appraisal, he shall bear legal responsibility.