Immunoassays
ELISA
Assay Development  Monoclonal Antibody Development
ELISA (Enzyme Linked Immuno-Sorbant Assay)
ELISA technology can be used for preclinical or clinical PK studies and for detection of host anti-drug antibodies (ADA), Some purposes and methodologies include:
- GMP lot release assay,
- affinity (Kd) measurements,
- quantitation of cytokines or other proteins produced by cells or in the body,
- triggering of signal transduction as detected by phosphorylated receptors, and other purposes.
At Marin Biologic, we have:
- Employed optical, fluorescent, luminescent, time-resolved and radioimmune (RIA) detection methods using either monoclonal or polyclonal antibodies.
- Proprietary methods:
- For reducing the background in complex matrix such as serum, plasma, or tissue extracts, and for
- Removing interferences such as analyte binding to proteins and receptors or interfering host antibodies of various types.
- Developed over 60 ELISAs, starting with producing our own monoclonal antibodies and polyclonal antibodies or screening commercial sources, and
- Validated over 30 methods for GLP or GMP use.
- MSD, Meso Scale Discovery platform for increased sensitivity, expanded range and decreased matrix effects.
We will be your project manager for the development of polyclonal antibodies at the vivarium of your choice.
Further use of your monoclonal and polyclonal antibodies might be for affinity purification of your drug or protein from mammalian or bacterial expression. Our scientists can consult with you about your final use for the ELISA assay and discuss various formats that can be designed into your assay development. Should you have an ELISA assay already developed and wish to have our scientists use it to test drug metabolism, drug stability or lot release we will employ your protocols.
For small molecules, a competitive type ELISA can be developed in which the analyte found in a matrix such as serum competes with a preparation of analyte-tagged (for example, with biotin) for binding to an immobilized antibody. With increased analyte in serum, there is reduced binding of the tagged analyte to the immobilized antibody, thus a reduced signal is measured.
Radioimmune Assay (RIA)
We develop RIAs and utilize these assays for detection of intact drug, drug metabolites, binding to serum proteins for drug disposition, and other studies requested by our clients when they need to perform assays in the same format that were previously submitted to the FDA. These assays may involve radioactive derivatives of their drug and detection by RIA.
AFFINITY OR Kd MEASUREMENT
We perform affinity of antibodies for their target antigen, or of a molecule for its receptor, or inhibition of binding by candidate antagonists, using ELISA-type methods, or a radioactive method for high affinities (sub micromole).
Monoclonal Antibodies
Often cell-based immunoassays require the pairing of two antibodies, one for capture and one for detection. Since polyclonal antibody affinities change over time as the T cells mature, an assay employing monoclonal antibodies may result in a more reproducible assay. Additionally, affinity purification using a monoclonal antibody will also result in reproducible yields.
Our scientists can consult with you about producing hybridomas that generate monoclonals with the desired characteristics. We will conjugate your hapten or peptide, or if your antigen is a protein, then we will suggest an immunization protocol. We will develop your screening assay or implement the assay you've developed and screen your initial cell cultures after fusion as well as your clones. We will deliver to you conditioned media for further screens or after consultation with you, purify the antibody and deliver the purified monoclonal antibodies as well as the hybridomas. If you need further characterization of the monoclonal antibodies, our scientists can discuss with you your needs and perform the needed analyses.
This partial list indicates the techniques we perform. Additional immunological assays can be found under Cellular Immunology.
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