The Amerlex-M system is a magnetic separation system for use in immunoassay. It combines the advantages of second antibody solid phase separation with liquid phase kinetics. Its use eliminates centrifugation during the separation of free and bound ligand. Amerlex-M donkey anti-rabbit reagent consists of magnetisable polymer beads coated with second antibody. The use of this reagent enables phase separation by introduction of a magnetic field. It is used where the primary antibody is of rabbit origin and is particularly suitable for iodine-125 radioimmunoassays as bound counts end up in the pellet.
- Magnetisable polymer beads coated with secondary antibody
- Simple magnetic separation eliminates centrifugation
- Minimises hands-on time by reducing tube handling
- Sufficient for 400 tubes in a typical assay
- Storage conditions at 2 to 4 °C
An Amerlex-M separator, consisting of detachable 50-tube rack and magnetic base, is available for use with Amerlex-M assays. Following addition of the donkey anti-rabbit reagent to the assay tubes, the rack containing the tubes is clipped onto the magnetic base. Primary antibody - with and without labelled ligand - bound to the second antibody on the beads rapidly migrates to the base of the tube, enabling separation of phases by decantation. Measurement of radioactivity in the pellet enables the amount of labelled analyte in the bound fraction to be calculated. The concentration of unlabelled analyte is determined by interpolation from a standard curve.
500 μl of Amerlex-M donkey anti-rabbit reagent is sufficient to bind at least 5 μg rabbit IgG. The reagent is supplied in a phosphate buffered solution, pH 7,4. Although the Amerlex-M reagent is designed for use in a magnetic separation protocol, conventional centrifugation can be used if preferred. Instruction on the use of centrifugation is given in the separation protocol. Note: Given the variation in assay conditions and protocols, it remains the responsibility of the user to optimise the use of Amerlex-M reagent in a particular assay.