This website contains information and allows for ordering human monoclonal antibodies (mAbs) directed against HLA, as well as sera containing HLA antibodies. In addition, mAbs to a limited set of red blood cell antigens can be ordered through this website. The mAbs have been developed by dr. Arend Mulder and colleagues in the National Reference Center for Histocompatibility Testing (NRC) headed by Prof. dr. Frans H.J. Claas, which is housed in the department of Immunology, Leiden University Medical Center, the Netherlands. The NRC is a non-profit organization for the development of the field of HLA and histocompatibility testing with the aim of acquiring and sharing knowledge on the structure and function of transplantation antigens. The overall aim of this preclinical work is to improve the results of both hematopoietic stem cell and solid organ transplantation.

Available information on mAbs

Antibody specificities listed on this website have been defined by complement dependent cytotoxicity (CDC)(for most MAbs). Where available, the eplet recognized by the mAbs can be found, as determined by HLAMatchmaker, based on single antigen bead analysis. These eplet analyses have been made possible through collaborations with René Duquesnoy (University of Pittsburg, USA) and Rico Buchli (Pure Protein, Oklahoma, USA). mAb isotypes and light chain usage have been defined by ELISA. Regular mAb orders are supernatants of heterohybridoma cultures. Further information on the mAbs and sera may be available and can be requested on a per case basis. The mAbs and sera available through this website are for research purposes only. The mAbs and sera have been used for a variety of purposes, including but not limited to tissue typing, flow cytometry, HLA blocking experiments and immunohistochemistry. Appropriate dilutions of mAbs and sera need to be established by the end user through titration. For some purposes, suggestions on appropriate dilution factors are available on request.

mAb isotypes

While the vast majority of mAbs has been generated by heterohybridoma technology, new mAb development in our laboratory involves recombinant technology. Most mAbs are of the IgM or IgG1 isotype. For some mAbs, multiple isotypes have been generated through recombinant technology. All recombinant versions can be found with the extension ".rec" in the mAb name.

Available information on sera

All serum specificities were determined by CDC assays. Additional reactivity in either CDC or single antigen bead assays cannot be excluded and should be assessed by the end user, if required.

Notify: Test samples have not been tested for presence of the virusses: Hepatitis B, Hepatitis C and antiHIV 1/2.

Available information on reagents

The IgM control serum is only suitable for CDC testing. IgM control serum is derived from a patient with a paraprotein reacting against human lymphocytes and is dithiothreitol (DTT) sensitive. The IgG blend and the IgM blend are a mixture of resp. IgG and IgM Human HLA Class I Monoclonal antibodies, covering most Class I HLA specificities. The IgM and IgG blend can also be used as controls in SPA-based assays. The IgM control serum is only suitable for CDC testing.


Test samples of sera and mAbs for feasibility studies can be requested free of charge (1 mL per sample), if available. Regular orders of mAbs and/or sera require a minimal volume of 5 mL with increments of 5 mL per product. Please note that we can run out of stock of specific sera due to limited volumes.

Test samples of reagents for feasibility studies can be requested free of charge (1 mL per sample). Regular orders of reagents require a minimal volume of 1 mL with increments of 1 mL per product.

Shipping costs: When ordering reagents only as non-commercial laboratory shipment cost of €40,- will be charged for 2024. When ordering reagents together with other sera or mAbs, the usual shipping costs of €250,- will be charged.


These products are intended for in vitro research purposes only. The National Reference Center for Histocompatibility uses its best efforts to develop a high-quality mAb and serum database and to verify that the data contained therein have been selected on the basis of sound scientific judgment. However, the National Reference Center for Histocompatibility makes no warranties to that effect, and National Reference Center for Histocompatibility shall not be liable for any damage that may result from errors or omissions in the database.