The accuracy of a DNA test is dependent upon a number of factors. The main factors which affect the accuracy/power of a paternity test are as listed:

The number of STR Loci (genetic locations) which are examined
As a rule of thumb, the greater the number of STR Loci that are examined, the more accurate and powerful you test becomes. Current technology allows up to 16 STR Loci to be tested for routine paternity tests. Laboratories which test all 16 STR Loci are offering premium tests. Unfortunately, due to a lack of awareness by the consumer, smaller laboratories often test 9 STR Loci or less but because the consumer is not aware that up to 16 STR Loci can be tested, lower quality tests are often performed. Genex provides a guarantee that all 16 Loci are tested for each paternity test.

The number of times that the laboratory performs the test
The current standard to ensure 100% accuracy is to run all paternity tests two times in parallel to ensure that the results are absolutely accurate. Genex runs all tests two times before the final test report is generated.

Testing is performed by qualified Ph.D Scientists
AABB requirements specify that all reports must be overseen and verified by a qualified Ph.D Scientist. Genex is staffed by multiple Ph.D Scientists who are qualified by AABB to sign and verify legal documents for court use.