As compounds increase in complexity, we continue to invest in the latest technology that best meets the needs of our clients for their ligand-binding assays. Spatial Proximity Analyte Reagent Capture Luminescence (SPARCL) is one such new technology that greatly improves our ability to process quickly and accurately client samples. Akin to ELISA and MSD assays, SPARCL likewise binds through specific antigen/antibody interaction. It is a reagent-based antibody capture luminescence assay that would be developed and validated on a per test article (TA) basis for determination of concentration in large molecule bioanalysis for PK or TK.
SPARCL is a proximity-dependent, non-separation, no wash, chemiluminescent detection method. In a SPARCL assay, a chemiluminescent substrate (acridan) is brought into the proximity of an oxidative enzyme (horseradish peroxidase, HRP) through the specific antigen/antibody interaction. A flash of light proportional to the quantity of analyte present in the sample is generated upon addition of a trigger solution containing H2O2 and para-hydroxycinnamic acid (pHCA) and decays in one second, eliminating any well-to-well signal cross talk. There is no need to remove excess reactants as a background reducing agent can be added to enhance signal-to-noise ratio by minimizing any signal from unbound reactants. This assay technology, applicable to both sandwich and competitive assays, has been implemented in formats with and without a solid phase. In the format with a solid phase, both the acridan compound and a specific capture antibody are coupled to solid phases (e.g., micro particles or microtiter plates); whereas, when the solid phase is omitted, the capture antibody is directly labeled with the acridan compound.
The first assays developed using the SPARCL technology show sensitivity for large molecule bioanalysis TK with <20 ng/mL in 10% matrix. This sensitivity is among the best for a ligand-binding assay. The assay is also very fast, with only a single 30-minute incubation required and no washing. By contrast, ELISA assays take ~6 hours to complete analysis for ~120 samples. With SPARCL we can process samples four times faster (120 samples in 1.5 hours = a potential for 480 samples in 6 hours). To learn if this assay is right for you, contact us at [email protected].