Obtaining DNA

• First, DNA is obtained from both the child and the alleged father by swabbing the mouth and isolating cells from the fluids gathered.
  
  

Amplifying DNA with PCR

• The DNA from both the man and the child is cut into sections by enzymes. These sections are then amplified--or multiplied--using the PCR procedure.
  
  

Applying Fluorescent Markers

• Fluorescent markers that bind to specific sequences of the DNA are applied to the sections. If the man is the father of the child, their DNA will contain similar patterns of fluorescence.
  
  

Constructing DNA Fingerprints

• In this method, the DNA of man and child are cut using special enzymes called restriction enzymes. The resulting fragments are spread out according to size using a technology called gel electrophoresis.
  
  

Comparing the DNA Fingerprints

• If the gel patterns formed by the DNA fragments show a certain degree of similarity between the man and child's fingerprints, the man will be declared the father of the child.