Magnesium and bead interference

The table below shows results from a compound interference study. We tested a panel of 24 compounds in a QC assay using our AlphaLISA® toolbox bead products. The information below can be used for guidance as to whether Mg2+ might interfere in assays involving particular bead products, and at what Mg2+ concentration interference might occur. These data are derived from single experiments and should serve more as a guide rather than a precise value, as it is unlikely you will be using the exact same assay design as used to generate the data below. Interference concentrations may vary depending on the assay components. It is possible your assay will tolerate higher or lower concentration than what is shown.



Tested up to 0.1M
Catalog NumberProductNo effect (10%)50% loss% of inhibition at max conc
AL125Streptavidin AlphaLISA Acceptor Beads>0.1>0.10
AL126Protein L AlphaLISA Acceptor Beads>0.1>0.10
AL127Anti-FITC AlphaLISA Acceptor Beads1.6E-027.3E-0260
AL128 (biotin)Anti-6xHis AlphaLISA Acceptor Beads1.2E-025.3E-0272
AL128 (GSH)Anti-6XHis AlphaLISA Acceptor Beads1.8E-032.6E-0286
AL129Anti-V5 AlphaLISA Acceptor Beads>0.1>0.10
AL130Anti-mouse IgM AlphaLISA Acceptor Beads7.6E-033.1E-0263
AL131Anti-chicken IgY AlphaLISA Acceptor Beads3.6E-02>0.120
AL132Anti-sheep IgG AlphaLISA Acceptor Beads1.0E-02>0.126
AL133Anti-GFP AlphaLISA Acceptor Beads>0.1>0.10
AL134Anti-MBP AlphaLISA Acceptor Beads3.2E-02>0.132
AL136Strep-Tactin AlphaLISA Acceptor Beads3.4E-02>0.144
AS102Protein A Alpha Donor Beads>0.1>0.10
AS103Anti-FLAG Alpha Donor Beads>0.1>0.10
AS104Anti-mouse IgG Alpha Donor Beads3.2E-025.1E-0252
AS105Anti-rabbit IgG Alpha Donor Beads>0.1>0.10
AS106Strep-Tactin Alpha Donor Beads>0.1>0.10
AL900AlphaLISA TruHits kit 2 ug/mL>0.1>0.117
AL900AlphaLISA TruHits kit 20 ug/mL1.0E-035.9E-0399

Refer to the figure below for more detail as to what the values in the table above indicate. Please note that the figure is provided as a general example to explain how the values in our interference tables were determined. The table above indicates that an assay testing the effect of MgCl2 using anti-6X His AlphaLISA Acceptor beads (with glutathione Donor beads) showed little effect on the assay signal at final MgCl2 concentrations up to 1.8 mM. MgCl2 did show a half-maximal inhibition of signal when used at a final concentration of 26 mM. When 0.1 M MgCl2 was included in the assay, 86% signal inhibition was observed.

interferencetesting16_ASK.jpg
Figure: Key for how the values in our interference tables are derived. The “no effect” concentration was obtained by extrapolating the MAX - 10% MAX counts. Refer to the table above for actual interference values for each toolbox bead product.