HLA Single Antigen Bead Detection Service

The development of human leukocyte antigen (HLA) single antigen bead (SAB) assay represents a major technical advance in the ability to detect, identify, and semi-quantify HLA antibodies, which has a significant impact on the field of organ transplantation. Creative Biolabs provides HLA single antigen bead assay to determine the antibody profiles against HLA precisely.

SAB Assay

SAB assay produces trusted results with high consistency and sensitivity and is considered to be the gold standard in HLA antibody detection. What's more, SAB assay performed on the multiplexed immunoassay platform is the most sensitive diagnostic method for HLA antibody detection and identification.

Multiplexed Immunoassay-Based SAB Assay

Multiplexed immunoassay platform utilizes about 100 unique beads which are distinguishable by a unique color address created by 2 fluorescent dyes incorporated at different ratios. Each bead is coated with multiple copies of a single recombinant HLA antigen. The assay detects the relative level of IgG antibody bound to each bead using indirect immunofluorescence. The beads are analyzed on a multiplexed immunoassay instrument, which measures the intensity of the fluorescent signal from the secondary antibody.

Fig.1 Principles underlying the HLA single antigen bead assay.¹

Each bead has one or more different types of HLA molecules attached. If the test serum contains an HLA antibody it will bind to the appropriate HLA molecule. The binding can be detected by second phycoerythrin (PE)-labeled anti-human IgG. When excited by one of the lasers built into the multiplexed immunoassay instrument, each bead gives a specific signal due to the unique intensity of fluorophore embedded in the bead. A second laser detects the fluorescent excitation produced by the PE on the second antibody. Finally, two signals indicate first the presence (PE fluorescence) and second the specificity (bead fluorescence) of the HLA antibody in the test serum.

Highlights

• A sensitive method for detection of HLA antibodies, which represents the current highpoint in the evolution of HLA antibody detection assays.
• Dissection and specificity determination of complex mixtures of HLA antibodies, which is not possible with other techniques.
• Identification of antibodies to alleles within the same antigen group.
• Identification of antibodies to DQA1, DQB1, DRB3, -4, -5, and DPB1, which is not possible using other antibody screening assays.

Workflow

Fig.2 Workflow of HLA single antigen bead assay.

As a leader in HLA antibody detection, Creative Biolabs offers a full range portfolio of assays for low- to high-resolution detection. We also offer the most cost-effective multiplex assays and a wide range of singleplex kits. For more information, please feel free to contact us directly.

Reference

1. Tait, Brian D. "Detection of HLA antibodies in organ transplant recipients–triumphs and challenges of the solid phase bead assay." Frontiers in immunology 7 (2016): 570. Distributed under Open Access license CC BY 4.0, without modification.