S-adenosylmethionine (SAM) 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 SAM might interfere in assays involving particular bead products, and at what SAM 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 0.001M
Catalog NumberProductNo effect (10%)50% loss% of inhibition at max conc
AL125Streptavidin AlphaLISA Acceptor Beads>0.001>0.0010
AL126Protein L AlphaLISA Acceptor Beads>0.001>0.0010
AL127Anti-FITC AlphaLISA Acceptor Beads>0.001>0.0010
AL128 (biotin)Anti-6xHis AlphaLISA Acceptor Beads>0.001>0.0010
AL128 (GSH)Anti-6XHis AlphaLISA Acceptor Beads4.0E-051.7E-0483
AL129Anti-V5 AlphaLISA Acceptor Beads>0.001>0.0010
AL130Anti-mouse IgM AlphaLISA Acceptor Beads>0.001>0.0010
AL131Anti-chicken IgY AlphaLISA Acceptor Beads4.3E-04>0.00123
AL132Anti-sheep IgG AlphaLISA Acceptor Beads>0.001>0.0010
AL133Anti-GFP AlphaLISA Acceptor Beads>0.001>0.0010
AL134Anti-MBP AlphaLISA Acceptor Beads>0.001>0.0010
AL136Strep-Tactin AlphaLISA Acceptor Beads>0.001>0.0010
AS102Protein A Alpha Donor Beads>0.001>0.0010
AS103Anti-FLAG Alpha Donor Beads>0.001>0.0010
AS104Anti-mouse IgG Alpha Donor Beads4.6E-04>0.00147
AS105Anti-rabbit IgG Alpha Donor Beads>0.001>0.0010
AS106Strep-Tactin Alpha Donor Beads>0.001>0.0010
AL900AlphaLISA TruHits kit 2 ug/mL>0.001>0.0010
AL900AlphaLISA TruHits kit 20 ug/mL6.4E-08>0.0010

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 SAM using anti-6X His AlphaLISA Acceptor beads (with glutathione Donor beads) showed little effect on the assay signal at final SAM concentrations up to 0.04 mM. SAM did show a half-maximal inhibition of signal when used at a final concentration of 0.17 mM. When 1 mM SAM was included in the assay, 83% 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.