Molecular genetic determination of human leukocyte antigens (HLA) using Luminex technology is based on a sequence-specific oligonucleotide (SSO) approach. In this method, HLA-specific probes are attached to microspheres, or beads. HLA PCR products bind to these probes only if they perfectly match the probe sequence. Each bead population carries only one specific probe. In a single assay, up to 100 different bead populations and thus sequence-specific probes can be used. For higher resolution assays, LABScan3D technology can accommodate up to 500 different bead populations.

The bead populations are quantified using two fluorescent dyes at varying concentrations, which are analyzed by the Luminex flow cytometer. One laser detects the fluorescence on the bead surface to distinguish bead populations, while a second laser measures fluorescence emitted by the labeled HLA PCR products bound to the probes. The final HLA typing result is determined by assessing the positive and negative binding reactions between the PCR products and the probes.