General and Assay Development

Q: What is the difference between read buffers? A: MSD® Read Buffers differ in their chemical formulations, allowing one (or more) buffers to be better suited to a specific assay application. The MSD Read Buffer Guide provides a description of each buffer and highlights its useful applications. Q: How does one read buffer out perform others in applications? A: The formulation of some buffers facilitates better results in either washed or non-washed assay formats or in specific types of applications. The MSD Read Buffer Guide provides detailed information on choosing the correct Read Buffer for your application. Q: How much secondary antibody do I use for my assay development? A: For initial assay development, it is recommended that a 1:1 primary:secondary antibody ratio be used. For example, 1 µg/mL primary detection antibody: 1 µg/mL secondary detection antibody. A recommended starting concentration for each antibody is 1 µg/mL (6.7 nM), and can be adjusted according to initial assay results. Q: What is the binding capacity of avidin and Streptavidin plates? A: For Standard plates, the avidin or streptavidin-coated electrode surface is capable of binding 0.3 picomole of capture antibody from solution. For High-Bind plates, the avidin or streptavidin-coated electrode surface is capable of binding 1.2 picomoles of capture antibody from solution. Q: How do I preserve and store a partially-read plate? A: Retain MSD plate packaging (bag and dessicant pouch). Make sure to keep the unused wells dry during the assay; do not put Read Buffer or any other diluents in unread wells. Following the partial plate read, remove the Read Buffer from the used wells and tap out all residual fluid onto paper towels. Seal the unused plate sectors with an adhesive plate seal. Return the sealed plate to the MSD plate bag (containing the dessicant pack) and place within a sealable plastic bag. Remove as much air from the bag as possible and seal. Store plates for up to 2 weeks at 4°C. Q: Where can I find information about immunogenicity assay development? A: The MSD Immunogenicity Applications technical presentation provides detailed information about using MSD technology to develop immunogenicity assays, including topics such as ELISA replacement sandwich immunoassays, bridging assays, drug tolerance, and neutralization assays. Q: Where can I find general information about MSD assay development and plate spotting? A: The MSD Immunoblot and General Notes technical presentation includes detailed information about MSD Immuno-Dot-Blot assays and general MSD assay development topics including plate spotting, appropriate assay volumes, plate binding capacity, appropriate signal levels, running a partial plate, blocking, and read buffers. Q: What are the dimensions of your 96- and 384-well plates? A: 96-Well Plate Parameters Measurement Overall Footprint 3.365 in. x 5.030 in. Overall Height 0.565 in. Well Spacing (Center-to-Center) 0.3543 in. (9 mm) Well Dimensions at Top 0.276 in. x 0.276 in. Well Dimensions at Bottom 0.252 in. x 0.252 in. Well Depth 0.460 in. Total Well Volume 410 µl Bottom of Wells to Resting Plane of Plate 0.105 in. 384-Well Plate Parameters Measurement Overall Footprint 3.365 in. x 5.030 in. Overall Height 0.400 in. Well Spacing (Center-to-Center) 0.1772 in. (4.5 mm) Well Dimensions at Top 0.1472 in. x 0.1472 in. Well Dimensions at Bottom 0.1222 in. x 0.1222 in. Well Depth 0.295 in. Total Well Volume 86 µl Bottom of Wells to Resting Plane of Plate 0.105 in. Well pattern centerline and footprint centerline are coincident.