The FOx technology uses fiber-optic-based surface plasmon resonance (FO-SPR) to directly measure an analyte of interest from blood, resuspended dried blood spots and other crude matrices. Providing accurate results from a range of sample inputs demonstrates the robustness and versatility of the FO-SPR technology.
- Serum
- Plasma
- Whole blood
- Dried blood spots
Case study: Dry blood spot sampling
Dry blood spots are an ideal method for patients to provide blood samples from home, with minimal transportation requirements. However, blood cell bursting, and the altered structure of analytes caused by the drying process, can influence the extraction efficiency.
In tests with infliximab (IFX), a monoclonal antibody used for the treatment of inflammatory bowel disease, the FO-SPR bioassay demonstrated that:
- The blood drying process did not affect analyte extraction or interfere with the bioassay antibodies.
- IFX was uniformly distributed across the blood spot on the paper.
- Non-specific binding due to blood cell bursting did not interfere with the FO-SPR bioassay.
FO-SPR can accurately detect antibodies in dried blood spots. The therapeutic drug antibody, infliximab (IFX), was spiked into blood and dried. The IFX concentration from the extract using FO-SPR correlated well with results using ELISA.