Bioassays are used for determination of the potency or biological activity of a substance, such as an antibody or hormone by comparing its effects with those of a standard preparation on a culture of living cells or a test organism. Such potency assays are a requirement for all biopharmaceutical products. The concentration or potency of a substance is estimated by measurement of the biological response that it produces. Bioassays are typically analyzed using the methods of biostatistics.

• Bioassays are central and critical for
  • Product development and manufacturing
  • Assuring continued quality, safety and efficacy of biopharmaceutical products
• Bioassays must be
  • Relevant: reflecting the mode of action (MoA) of the respective pharmaceutical
  • Reliable
  • Standardized: equipment, materials, procedure
• According to Ph. Eur. in vivo assays should be replaced by in vitro assays or physicochemical methods if possible
• Several cell-based bioassays are specified in the European Pharmacopoeia; those are performed following the monograph
• Bioassays are performed according to GMP at NewLab

Assay types (in vitro)

• Cell-based potency assays for EPO, PTH, G-CSF, GM-CSF
• Antiviral cell-based assays for measuring the potency of Interferons (IFN-α, IFN-β)
• Flow cytometry assays
  • Principle: Laser-based flow cytometry measures microscopic particles (0.2 – 150 µm) suspended in a stream fluid. It allows simultaneous multiparametric analysis of the physical and/or chemical characteristics on single cell level in “real time” (several thousand particles/second). In general the particle size is detected by the Forward Scatter (FSC), the particle granularity is detected by the Sideward Scatter (SSC) and the fluorescence is detected by an argon laser (488 nm) and a red diode laser (633nm). Up to four colours can be measured in parallel. 
  • Applications
    • Antigen, receptor or ligand density (e.g. binding assays)
    • Intracellular protein expression
    • Transgenic products in vivo, particularly the green fluorescent protein (GFP)
    • Enzyme activity
    • Phospho-protein analysis
    • Apoptosis
    • Viability
    • Cell Cycle Analyses
    • Membrane potential
    • Changes in intracellular pH, intracellular calcium and intracellular glutathione
    • Detection of soluble analytes by bead array technology
    • Various combinations (DNA/surface antigens etc.)
  •  Particles that can be measured
    • Cell lines
    • Blood cells, bone marrow, tumour cells
    • Plant Cells
    • Nuclei
    • Yeast
    • Bacteria
    • Viruses
  • Advantages
    • Fast analysis on single cell level
    • Complex heterogeneous samples can be tested
    • Multiple markers can be correlated simultaneously

    FACSCalibur™ unit is GMP-qualified at NewLab

• Reporter gene assays
  • Luminescence assays
  • Fluorescence assays
• Assays for monoclonal antibodies
  • Binding assays
  • Potency assays
• Cell proliferation assays
• Cell survival assays
• Competitive assays

Assay readouts

• Fluorescence
• Absorbance
• Luminescence
• Analysis by flow cytometry

Statistical evaluation

• EC₅₀ determination
• Four parameter fit
• Five parameter fit
• Parallel line analysis

Services

• Method development
• Method transfer
• Method optimization
• ICH-compliant method validation
• Lot release testing for drug substance and drug product
• Stability testing