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For more information, please call
416-479-3773 or email
[email protected]
or send us a message here:

Large Molecule/Biomarkers

Custom Biologics™ is recognized for its expertise in the development and validation of ligand binding and cell-based bioassays which measure biomarker profiles and expression levels as well as the binding, functional activity and immunogenicity of biologics, monoclonal antibodies and biosimilars.

Our assays are designed to support the unique requirements of drug development programs. We employ established laboratory and statistical methods to conduct potency, comparability, stability and lot release testing of biosimilars. Method transfer protocols exist to guarantee that testing requirements proceed smoothly and on time.

Our assays can be utilized in the course of research and development programs or as validated GMP- compliant assays suitable for stability analysis, clinical trials and clinical lot release testing.


Cell-based bioassays

Cell-based bioassays are designed to assess the mechanism of action (MOA) and potency of biologics. EC50 and relative potency values of the test biologic are determined using rigorous statistical methods. Our different cell-based assay platforms include: Enzymatic/reporter-based assays, CDC, ADCC, potency, proliferation, migration, inhibition and cytotoxicity.

Ligand Binding Assays (LBA) - Biomarkers

Ligand binding assays are employed to characterize the receptor binding properties of biotherapeutics and to deduce the pharmacokinetic and toxicokinetic profiles of biotherapeutics. Expression levels and profiles of biomarkers in diseased and healthy state biological matrices are quantified using sensitive assay platforms. Test platforms include: Absorbance, luminescence, fluorescence and electrochemiluminescence.

Immunogenicity Assays

The immunogenicity of a biologic must be evaluated for the production of in-vivo anti-drug and neutralization antibodies as these can impact its therapeutic efficacy. Custom Biologics has developed and validated sensitive and robust assays to detect these antibodies. Test platforms include: LBA and cell-based bioassays as well as Bio-Layer Interferometry.

Cell Line Banking

Custom Biologics has prepared Master and Working cell banks to ensure quantity and consistency in the course of development programs, validation, stability and lot release testing. Our cell banks are tested for sterility and stored in a controlled environment under liquid nitrogen vapour. All cell line work is performed in our Biosafety Level-2 facility.

Protein Analytical Characterization

All biologics are tested for purity, cross reactivity, degradation and receptor binding. Certificates of Testing document all analytical procedures. Test platforms include: SDS-PAGE, Western blotting, isoelectric focussing, gel documentation imaging and reporting.

Residual Contamination Testing

Residual levels of host cell proteins in drug samples are quantified using sensitive, commercial or custom made ligand binding/immunoassay platforms. Residual levels of host cell nucleic acids and expression plasmid DNA are measured using quantitative, real time, mulitplex PCR-based assays. Target organisms include: E. coli, CHO, Goat, HEK293, tobacco plant and VERO cells.

Stability/Lot Release Testing

Validated assays for GMP-compliant stability and clinical lot release testing of biologics can be performed according to fixed and controlled schedules that adhere to stipulated testing requirements and turn-around times.


Custom Biologics offers a comprehensive range of sophisticated methodologies to support the biological characterisation, comparability, lot release and clinical assessments of biotherapeutic monoclonal antibodies and their biosimilars or biobetters.

Click here for a full list of biosimilars and their associated assays