Cavidi

Blood tests for Alzheimer's arrived in 2025: two FDA clearances, the first clinical guideline, and a real shift. A blood draw can now triage pathology that used to need a lumbar puncture or a PET scan. But the two biomarkers doing the work aren't equally easy to measure. For amyloid-beta, the wall isn't sensitivity; it's precision, in a plasma matrix actively working against you. New on the blog: why plasma amyloid-beta is analytically unforgiving, how the platforms really compare, and where signal-amplified ELISA honestly fits, with a recent thesis as the worked example.

Every ELISA has a floor: a concentration below which your target blends into the blank and the sample comes back "below range." BOLD (Binding Oligo Ladder Detection) moves the floor. By amplifying the detection signal, it shifts the whole response curve toward lower concentrations, typically improving the limit of detection 10–100× (up to ~200× under optimal conditions). Targets that sat beneath a standard assay's detection threshold cross back above it. Same antibody pair, same plate, same readout, one added step at room temperature. You're not rebuilding the assay. You're extending where it can still see. What you gain depends on your target and matrix, but this is the shape of it. Contact Jonathan Royce to get started. #Immunoassay #ELISA #AssayDevelopment #Exazym #Cavidi

Standard ELISAs often can't detect IL-4 at clinically relevant levels, and buffer performance doesn't guarantee plasma performance. A 60-second look at why that matters, and what researchers are doing about it. Watch the full webinar: https://bit.ly/4yZQLV5 #Immunoassay #ELISA #Cytokines #IL4 #Exazym #Cavidi

Your ELISA standard curve flattens at the bottom, and your lowest samples come back "below range." It's easy to read that as a failed run. It usually isn't. That flat bottom is the assay showing you its floor, and the floor is set by something we don't look at closely enough: the blank, and how much it scatters. New on the blog: why the bottom of your curve goes flat, what's actually setting your detection limit, and the order of operations for pushing it lower, including the counterintuitive reason more signal often doesn't help.

Every ELISA has a sensitivity floor. What if yours is set by the kit, not the biology? Same human IL-4 sandwich ELISA, same IL-4 calibrators, run side by side. The one change: Exazym® StreptaClick® Primer, an engineered streptavidin, binds the biotinylated detector antibody a standard kit already uses and adds BOLD (Binding Oligo Ladder Detection) signal amplification. The orange curve is what happened. It pulls away from the standard ELISA exactly where it matters, at the low end, and the detection limit dropped from 0.195 to 0.025 pg/mL. About 8× lower, on the same kit, with no new instruments. It's a single feasibility run, and we put all of it in the open: the calibration data, the CVs, dilution linearity, spike recovery in plasma, and a protocol you can adapt to your own target. If your assay keeps bottoming out before your samples do, this one's worth the read: https://lnkd.in/egdwwCuN #IL4 #ELISA #Immunoassay #Biomarkers #Exazym #Cavidi

A lot of sensitivity numbers fall apart when you read the methods. This one holds up. In the SARS-CoV-2 benchmark, the standard ELISA and the BOLD-amplified version shared everything — same capture and detection antibodies, same sample, same plate, same reader. Only the amplification step differed. That's why the 67× is a figure you can cite without a caveat. See inside the SLAS (Society for Laboratory Automation and Screening) Technology paper. We read the experiment closely in our latest article → https://lnkd.in/eAaaUHsC #ELISA #Immunoassay #Biomarkers #AssayDevelopment #Exazym