FICT Test Strip Production Process¶
The FICT (Fluorescence Immunochromatographic Technology) test strip is a laminated assembly of engineered membranes and pads. Its performance — sensitivity, precision, and lot-to-lot consistency — is determined by how precisely each layer is manufactured and assembled. This page walks through the full production sequence.
The 8-Stage Process¶
| Stage | Process | Key parameters | Quality gate |
|---|---|---|---|
| 1 | Membrane coating | T-line/C-line reagent dispense rate, line width | Line uniformity check |
| 2 | Drying | Temperature, humidity, dwell time | Residual-moisture check |
| 3 | Conjugate pad preparation | Antibody–fluorophore conjugation ratio, dispense volume | Conjugation QC + pad uniformity |
| 4 | Sample pad treatment | Buffer composition, blocking, drying | pH & flow-rate check |
| 5 | Lamination | Alignment, pressure | Visual + dimensional inspection |
| 6 | Cutting | Strip width (3–5 mm), edge quality | Width tolerance check |
| 7 | Cassette assembly & pouching | Strip insertion, desiccant, seal integrity | Seal + label verification |
| 8 | Labeling & packaging | Lot number, expiry, IFU insert | Final QC (FQC) + OQC |
Stage-by-Stage Detail¶
1. Membrane Coating¶
The nitrocellulose membrane carries the test (T) and control (C) lines. Capture antibodies (or antigens) are dispensed as two fine lines using a continuous film stripper.
- What matters: uniform line width and reagent volume. A 10% variation in dispensed volume translates directly into signal (CV%) variation.
- Control: line-width measurement and fluorescence-intensity checks on the dispensed membrane.
2. Drying¶
Coated membranes are dried under controlled temperature and humidity.
- Why it matters: incomplete drying causes line diffusion and high background; over-drying degrades antibody activity.
- Control: residual-moisture verification and activity spot-checks.
3. Conjugate Pad Preparation¶
Detection antibodies are conjugated to fluorescent labels (fluorophores/microspheres) and sprayed onto a glass-fiber conjugate pad. The conjugation chemistry is covered in the Research Center.
- What matters: conjugation ratio, unbound-label removal, dispense uniformity.
- Control: conjugation efficiency and pad lot QC.
4. Sample Pad Treatment¶
The sample pad buffers and pre-treats the sample for consistent lateral flow.
- What matters: buffer pH, blocking agents, and uniform saturation.
- Control: pH and wicking-rate checks.
5. Lamination¶
The membrane, conjugate pad, sample pad, and absorbent pad are laminated into a continuous card on an automatic laminating machine.
- What matters: precise overlap — gaps cause flow failure; excessive overlap wastes sample.
- Control: dimensional inspection and flow-function testing.
6. Cutting¶
Laminated cards are cut into individual strips (typically 3–5 mm) with a high-speed cutter.
- What matters: consistent strip width and clean, non-delaminating edges.
- Control: width tolerance measurement per batch.
7. Cassette Assembly & Pouching¶
Strips are inserted into plastic cassettes, sealed in foil pouches with desiccant.
- What matters: correct orientation, desiccant present, hermetic seal (moisture protection).
- Control: seal-integrity and label-accuracy verification.
8. Labeling & Packaging¶
Cassettes are labeled with lot number and expiry, and packed with the IFU insert.
- What matters: traceability (lot number) and regulatory compliance (IFU present).
- Control: FQC (final QC) before release, OQC (outgoing QC) before shipment.
Process Summary Diagram¶
Coating → Drying → Conjugate → Sample pad → Lamination → Cutting → Assembly → Packaging
↓ ↓ ↓ ↓ ↓ ↓ ↓ ↓
Line Moisture Conj. QC pH/flow Alignment Width Seal+label FQC/OQC
FAQ¶
How long does a full production run take? A standard lot runs through all stages within a single controlled cycle; total lead time depends on lot size and drying dwell times (see B2B Resources for procurement timelines).
Why is the membrane the most critical component? It carries both the capture lines and the migration surface — coating uniformity is the single largest determinant of CV%.
For the quality gates applied at each stage, see In-Process Quality Control.
Authored by: Migibio Clinical & Scientific Affairs, Guangzhou Magic Biotech Co., Ltd.
Reviewed by: Migibio R&D Quality Committee
Last updated: 2026-08-14
Disclosure: Migibio (Guangzhou Magic Biotech Co., Ltd.) is the manufacturer of the FIA680/FIA880 analyzers and FICT reagents referenced in this content. See our Editorial & Review Policy.