Cell Based Assays Using MSD

The MSD platform can aid in the development of challenging cell based assays and increase the efficiency of cell based assays currently performed by FACS, ELISA and other methods.  Whole cells can easily bind the carbon electrode at the bottom of each well allowing detection of the cell surface membrane proteins.  The ability of cells to directly bind the electrode greatly expands the techniques used with cell based assays.  MSD can be used for following CBA applications:

  • Hybridoma screening
  • Screening for antibodies against cell surface proteins
  • Immunogenicity Nab assays
  • Ligand-receptor inhibition assays


MSD Versus FACS Analysis

In some cases, the MSD platform can be used to replace assays performed by FACS.  Cells can be bound directly to the bottom of the well enabling proteins on the cell surface to be detected quickly and easily without the complications of cell sorters.   For analysis of cell surface markers, MSD has many advantages over FACS such as:

  • The instrumentation is easier to use – two clicks and samples are read
  • Less cells required for analysis
  • Less sample volumes required
  • Faster read time (70 seconds vs. one hour)
  • No centrifugation step required
  • Higher throughput
  • More cost effective

Performing Cell Based Assays using MSD

PBL owns a Quickplex SQ 120 MSD instrument that is fully validated and ready for GMP and GLP studies.  The general process for performing a cell based assay using the Quickplex SQ 120 instrument is as follows:

  1. Bind the cells to the plate by adding the cells in PBS to each well and incubating for 1 hour at 37 degrees for one hour.
  2. Wash the wells three times with PBS.
  3. Add 25 microliters of primary antibody that binds the cell surface protein.
  4. Add 25 microliters of detection antibody that binds the primary antibody.
  5. Wash the plate, add read buffer and read the plate.


Pacific BioLabs