Whole-Blood Compatible Fluorescent Immunoassay for Vitamin D Status Assessment
The 25-OH Vitamin D FIA Test is a fluorescent immunoassay for quantitative measurement of 25-hydroxyvitamin D (calcidiol) — the principal circulating form of vitamin D and the accepted clinical indicator of vitamin D status. Unlike conventional serum-based assays, this test accepts whole blood directly, eliminating the centrifugation step that is impractical in point-of-care environments.
Built on a validated anti-25-OH-VD antibody optimized for one-step lateral flow FIA, the assay delivers results in 15 minutes with excellent within-run precision. Performance has been validated against the Roche automated platform across 60 clinical samples spanning the full clinical range.
Key performance and workflow advantages over conventional vitamin D immunoassays.
Accepts whole blood directly — no centrifugation required. Reduces pre-analytical steps and enables true point-of-care testing in resource-limited settings.
Single-step protocol completes in 15 minutes vs. 25 minutes for two-step competitors. No intermediate wash or incubation steps needed.
All reagents are liquid-stable at 2–8°C. No lyophilized components, eliminating reconstitution errors and cold-chain complexity.
Covers 5–100 ng/mL — spanning the clinically critical deficiency, insufficiency, sufficiency, and toxicity zones in a single assay.
Within-run CV ≤8.5% across the analytical range (n=10 per level). Consistent performance at both the deficiency threshold (6.75 ng/mL) and normal range (32.4 ng/mL).
Strong method correlation demonstrated across 60 clinical serum samples spanning the full clinical range (5–100 ng/mL), benchmarked against Roche platform.
All data generated using Sekbio's anti-25-OH-VD antibody pair in an FIA sandwich format.
Five non-zero calibrators spanning 6.75 to 54 ng/mL demonstrate consistent dose-response with CV ≤7% per level (n=3 replicates). The blank (S0) produces negligible T/C signal, confirming low non-specific binding.
| Calibrator | Conc. (ng/mL) | Avg. T/C | CV (%) |
|---|---|---|---|
| S0 — Blank | 0 | 0.00 | 18% |
| S1 | 6.75 | 0.09 | 5% |
| S2 | 16 | 0.39 | 7% |
| S3 | 32.4 | 1.03 | 6% |
| S4 | 54 | 2.70 | 6% |
| T/C = Test line / Control line signal ratio. n=3 replicates per calibrator level. | |||
Ten replicates at two clinically relevant concentrations (6.75 ng/mL and 32.4 ng/mL). Both levels achieve CV well within IVD acceptance criterion of ≤10%.
| Concentration (ng/mL) | Replicates (n) | Avg. T/C | CV (%) |
|---|---|---|---|
| 6.75 | 10 | 0.09 | 7.3% |
| 32.40 | 10 | 0.93 | 8.5% |
| Acceptance criterion: CV ≤ 10% (IVD industry standard). | |||
Sixty de-identified clinical samples were measured in parallel using the Sekbio 25-OH-VD FIA and the Roche reference platform. Results show strong concordance across the clinical range of 5–100 ng/mL.
The 25-OH-VD antibody pair is validated across multiple IVD formats and clinical contexts.
Quantitative whole-blood 25-OH-VD measurement for population-level screening in primary care, community health, and routine wellness programs.
Rapid VD status assessment in prenatal care, neonatal screening, and pediatric nutrition monitoring without venipuncture-derived serum.
Antibody pair available as OEM raw material for FIA lateral flow manufacturers seeking a validated 25-OH-VD capture/detection pair for integration.
Optimized for fluorescence reader-based analyzers used in hospital point-of-care settings, urgent care, and remote-site diagnostics.
Request the full technical datasheet, antibody pair specifications, or discuss OEM supply and partnership arrangements with our team.