Anti-Rituximab Antibodies

Ideal for bioanalytical assays supporting preclinical research and clinical drug monitoring

Bio-Rad offers five ready made anti-idiotypic monoclonal antibodies to the chimeric rituximab (Rituxan®) antibody.

Anti-rituximab antibodies are ideal for use in direct ELISA, pharmacokinetic (PK) bridging assays and to develop and calibrate immune response (IR) assays to measure the anti-drug antibody (ADA) response in patient sera.

Antibody MCA2260, clone MB2 A4, was developed in rat using traditional antibody methods.

A further four antibodies were generated using the HuCAL® recombinant antibody library and phage display technology.

Antibody generation using HuCAL technology results in highly specific and sensitive antibodies, ideal for PK and PD assays. Antibodies are fully human, so are also perfect as controls or calibrators for ADA assays. The in vitro production of recombinant antibodies means that there is a consistent, secure supply throughout preclinical development and clinical trials, avoiding the need to develop new reagents.

More information about anti-idiotypic antibodies and their binding types and properties

Anti-biotherapeutic antibody quality control and characterization


Antibodies Specific to Rituximab

Product Code Clone Format Affinity KD, nM Assay Development Recommendations
HCA186 AbD18423 Monovalent Fab-FH1 0.13 PK bridging ELISA with MCA2660P as detection antibody
HCA201 AbD18423_hIgG1 Human IgG1 0.13* ADA assay
MCA2260 MB2 A4 Rat IgG2a Unknown Direct ELISA
MCA2260P MB2 A4 Rat IgG2a
HRP labeled
  PK bridging ELISA with HCA186
MCA2260F MB2 A4 Rat IgG2a
FITC labeled
  Detection of rituximab in flow cytometry
HCA062 AbD2844 Fab-dHLX-MH2 10.0* Direct ELISA
HCA062P AbD2844 Fab-dHLX-MH2
HRP labeled
  PK bridging ELISA
HCA061 AbD2842 Fab-dHLX-MH2 4.9* Direct ELISA
HCA061P AbD2842 Fab-dHLX-MH2
HRP labeled
  PK bridging ELISA

Table 1 Antibody Specifications
1 F=DYKDDDDK-tag H=His-6-tag;
2 Bivalent mini-antibody, M=c-myc-tag, H=His-6-tag);
* Affinity measured in the monovalent Fab format


Pharmacokinetic Assay - Bridging ELISA

Pharmacokinetic (PK) Assay

Schematic image of PK Bridging ELISA. Anti-idiotypic capture antibody, Fab format (purple), monoclonal antibody drug (gold), anti-idiotypic detection antibody, Ig format (blue), labeled with HRP

PK assay, bridging format, using rituximab antibody

Figure 1: PK assay, bridging format, using, antibodies HCA186 and MCA2260P

Anti-rituximab antibodies, product codes HCA186 and MCA2260P

Figure 1: Anti-rituximab antibody, clone AbD18432 (HCA186), was coated on a microtiter plate at 1.0 µg/ml and left overnight. After washing and blocking with 5% BSA in PBST, rituximab spiked in 10% human serum was added in the given concentrations. Detection was performed by adding HRP conjugated anti-rituximab antibody, clone MB2A4 (MCA2260P), 3.0 µg/ml in HISPEC assay diluent (BUF049), plus QuantaBlu™ fluorogenic peroxidase substrate. Data are shown as the mean of three experiments.

Protocol: PK bridging ELISA for use with anti-rituximab antibodies


Anti-Drug Antibody Assay – Bridging ELISA

Anti-Drug Antibody (ADA) Assay – Bridging ELISA

Schematic image of ADA bridging assay. Monoclonal antibody drug as capture antibody and detection antibody labeled with HRP (gold), fully human anti-idiotypic antibody, Ig format (blue)

ADA assay, bridging, format using Rituximab antibody

Figure 2: ADA assay, bridging, format using antibody HCA201

Human anti-rituximab antibody, product code HCA201

Figure 2: Rituximab was coated at two different concentrations (1.0 µg/ml and 1.5 µg/ml) on a microtiter plate and left over night. Anti-rituximab antibody, clone AbD18423_hIgG1 (HCA201), titrated into 10% human serum in the given concentrations, was then added. Detection was performed by adding HRP conjugated rituximab in HISPEC assay diluent, plus QuantaBlu fluorogenic peroxidase substrate. Data are shown as the mean of three experiments.


Determination of Antibody Specificity

Specificity of anti-rituximab antibody HCA186
Figure 3: Specificity of anti-rituximab antibody HCA186

Human anti-rituximab antibody, product code HCA186

Figure 3: Demonstration of specificity to rituximab. Antigens (human serum as well as chimeric, humanized and human antibodies of the type IgG1/kappa) were coated at 5.0 µg/ml on a microtiter plate and left over night. After washing and blocking, anti-rituximab antibody, clone AbD18423 (HCA186) was added. Detection was performed using HRP conjugated mouse anti-His tag antibody (MCA5995P).


Licensed Use: For in vitro research purposes and for commercial applications for the provision of in vitro testing services to support preclinical and clinical drug development. Any re-sale in any form or any other commercial application needs a written agreement with Bio-Rad.

RITUXAN® is a registered trademark of Biogen Idec, Inc. USA. HuCAL® is a registered trademark of MorphoSys AG. QuantaBlu™ is a trademark of Thermo Fisher Scientific.