The UCLA International DNA Exchange was established in 1993 with 63 participants. The goal of the exchange was to provide samples of DNA from the same individuals to laboratories for testing and to compare the results obtained using different methods and different reagents. The exchange has been graded since 1993 and many laboratories have used their participation in the exchange to satisfy proficiency testing requirements. Currently, 125 laboratories participate in the exchange ( worldwide participation page ). The end of 2001 marked the completion of 51 DNA exchanges, including 330 preparations for Class II DNA typing, and 221 for Class I DNA typing. The participating laboratories employ a variety of PCR-SSP and PCR-SSO DNA typing approaches, but the number of laboratories reporting direct sequencing of HLA genes is increasing.

The results of the DNA exchanges have shown a very high concordance among laboratories performing DNA-based HLA typing. The exchanges have confirmed the superior inter-laboratory accuracy and reproducibility of DNA typing methods when compared with the results of serological testing. The DNA exchanges have also provided a bank of extremely well characterized DNA samples, with alleles confirmed by many laboratories using different methods. These samples have been assembled, catalogued and can be purchased individually or in panels. ( see reference panel section )