Amyloid β (Aβ or Abeta) denotes peptides of 36–43 amino acids that are crucially involved in Alzheimer's disease as the main component of the amyloid plaques found in the brains of Alzheimer patients. The peptides result from the amyloid precursor protein (APP), which is being cut by certain enzymes to yield Aβ. One of the most common isoforms is Aβ1-42.^{1, 2}

Aβ1-42 Protein Control Solution is used as a standard control for “MagQu” Amyloid β 1-42 IMR Reagent (MF-AB2-0060). The antibody conjugated on the surface of Fe3O4 magnetic particles (~ 50 nm) could bind with Aβ1-42 protein and form clusters. With the increase of cluster, the signal of ac susceptibility ( χac ) will decrease in the applied ac magnetic field. That is the principle of Immuno Magnetic Reduction (IMR). By measuring the reduction of χac, we can quantify the Aβ1-42 protein in the sample easily and accurately.³

References

1. M.J. Chiu, S.Y. Yang, T.F. Chen, J.J. Chieh, T.Z. Huang, P.K. Yip, H.C. Yang, T.W. Cheng, Y.F. Chen, M.S. Hua, and H.E. Horng, “New assay for old markers-plasma beta amyloid of mild cognitive impairment and Alzheimer’s Disease”, Curr. Alzheimer Res. 9, 1142 (2012).
2. M.J. Chiu, Y.F. Chen, T.F. Chen, S.Y. Yang, F.P. Gloria Yang, T.W. Tseng, J.J. Chieh, J.C. Rare Chen, K.Y. Tzen, M.S. Hua, and H.E. Horng, “Plasma tau as a window to the brain-negative associations with brain volume and memory function in mild cognitive impairment and early alzheimer's disease”, Human Barin Mapping, 15 Oct. (2013).
3. Che-Chuan Yang, Shieh-Yueh Yang, Jen-Jie Chieh, Herng-Er Horng, Chin-Yih Hong, Hong-Chang Yang, K. H. Chen, B. Y. Shih, Ta-Fu Chen, and Ming-Jang Chiu, “Biofunctionalized magnetic nanoparticles for specifically detecting biomarkers of Alzheimer’s disease in vitro”, ACS Chem. Neurosci. 2, 500 (2011).