Human blood, hair, saliva, oral cells and bones can all be used for paternity testing, which uses the theories and techniques of medicine, biology and genetics to determine the morphological structure or structure of offspring and parents. Similar characteristics in physiological functions, analyze genetic characteristics, and determine whether parents and children are biologically related.
The steps for DNA paternity testing are as follows:
Step 1: DNA extraction
Extract the DNA contained in the sample cell nucleus, and then perform certain purification. Remove impurities from the sample.
Second step: PCR amplification
The Chinese name of PCR is polymerase chain reaction. Simply put, the step of PCR amplification is to pass the fragments we need through enzyme To promote the reaction, a large number of copies are made on a PCR machine, amplifying it to the extent that it can be seen through some special instruments.
The third step: post-PCR reaction
This step is mainly the preparation stage for sequencer detection. Open the double-stranded DNA and add some internal standards for detection. Mainly is the length of the fragment used to mark the detection.
Step 4: Capillary sequencer detection
Because DNA is charged, through capillary electrophoresis, the electrophoresis speeds of different DNA fragments are different. At the same voltage, the same Under the electrophoresis time, the swimming distance is different. These different distances can be distinguished by the measurement of the internal standard added in the early stage. At the same time, they can be displayed on the computer through certain software to facilitate the detection personnel to process and analyze the data.
Step 5: Analyze the data and issue a report
The main task is for the testing personnel to analyze, summarize and calculate the results, and then issue identification conclusions and reports.