Glial Fibrillary Acidic Protein (GFAP) is a cytoskeletal, intermediate filament protein found predominantly in astrocytes. As levels of GFAP are higher surrounding Aß plaques and increase as tau accumulates, blood GFAP levels has been investigated as an indicator of neurological injury1 and as a potential marker of disease progressing in diseases such as Alzheimer's disease pathogenesis.1,2
Beckman Coulter has created a research use only (RUO), GFAP one-step sandwich assay* to measure GFAP from plasma. In this study, the analytical performance characteristics for the plasma GFAP immunoassay currently under development were evaluated on the Beckman Coulter Access 2 and DxI 9000 Immunoassay Analyzers.†
The study found:
- The Beckman Coulter RUO GFAP assay achieved highly sensitive results in ~30 minutes
- High-throughput and automated precise results were comparable to the Quanterix GFAP RUO assay with r=0.998
- Cross reactivity was not detected on either the DxI 9000 or Access 2 analyzer when investigating potential cross reactants such as amyloid beta (Aß) 1-40, or Aß 1-42
- Interference was not detected with therapeutic drugs used to treat Alzheimer’s disease nor with common drugs, endogenous proteins, and lipid-based interferents
- Limit of blank (LoB), Limit of Detection (LoD), and Limit of Quantitation (LoQ) were acceptable on both the Access 2 and DxI 9000 analyzers, with values on the DxI 9000 analyzer being approximately half of those on the Access 2 analyzer