Multiplexing is a technique that allows multiple analytes to be quantitated within a single well. Multiplexing saves time by cutting down on the number of plates that must be processed and also saves on samples amounts since the same 20 microliter sample can be analyzed up to ten different ways. Multiplexing is invaluable when assessing toxicity, determining the mechanism of action (MOA), or for biomarker discovery assays. Any time multiple analytes needs to be quantitated from a single sample, multiplexing will prove invaluable.
Meso Scale Discovery provides two different type of multiplexing:
- V-Plex – Multiplexing plates that are validated by MSD and can be used by the user without any preparation. Preconfigured panels are available but panels can also be customized by selecting analytes from a list of validated panels. The custom plates are then prepared and validated by MSD.
- U-Plex – Multiplexing plates that can be customized by the user but are not validated and requires user preparation. U-Plex assays require the user to perform a biotin-strepavidin linkage reaction to bind proteins to the electrode but allows for antibody combinations that are not possible with the V-Plex kits.
The “V” in V-Plex stands for Validated. All V-Plex plates provided by MSD undergo a rigorous validation and are shipped to the user with a certificate of analysis (CofA). The validation performed by MSD includes:
- Percent recovery of each analyte and % CV
- LLOQ and ULOQ
- Percentage of nonspecific binding
- Standard curve data for each analyte with % CV for each concentration
Full GLP and GMP validations for your product are available available through PBL. For a complete list of available V-Plex panels please contact PBL.
The “U” in U-Plex stands for “You” as in you prepare the multiplexing plates. Any combination of analytes can be measured using the U-Plex system. MSD has designed a biotin-streptavidin system that makes this as easy as possible. There are over 75 biotin labeled antibodies available through MSD and many more that can be made by PBL. The biotin labeled antibody is then linked to a “U-Plex Linker” via a biotin-steptavidin binding. The U-Plex linker can attach to specific locations on the plate.
Multiplexing at PBL
Pacific BioLabs can perform all your multiplexing needs. Custom U-Plex assays can be prepared by labeling an antibody specific to your analyte with biotin. U-Plex assays can be fully validated by PBL for GMP and GLP applications. V-Plex assays can be purchased through MSD and performed by PBL. Additional validation may be needed for GMP and GLP regulated studies and PBL has the experience and the expertise to develop, validate and perform the routine testing for mutliplexed MSD applications.