# Lyophilized Reagent Technology for Room-Temperature POCT
## Abstract
Lyophilization (freeze-drying) enables room-temperature storage of temperature-sensitive POCT reagents, eliminating cold chain requirements. This application note details lyophilization protocols for lateral flow strips, PCR reagents, and CRISPR-based diagnostics for POCT manufacturers.
## Introduction
Cold chain logistics account for 30-40% of POCT reagent costs in developing markets. Lyophilized reagents maintain stability at 25-30°C for 12-24 months, reducing shipping costs and expanding market access. However, lyophilization requires optimization to preserve biomolecule activity.
Due Bio, established in 1987, specializes in lyophilized reagent formulations for IVD Reagents OEM/ODM partners. Our lyophilization platform supports lateral flow strips, microfluidic PCR cartridges, and CRISPR detection reagents.
## Materials Required
– Lyophilizer with programmable temperature control
– Cryoprotectants (trehalose, sucrose, mannitol)
– Protein stabilizers (BSA, gelatin, PEG)
– Lyophilization vials or lateral flow cassettes
– Residual moisture analyzer
– Stability chambers (for post-lyophilization testing)
## Step-by-Step Protocol
1. **Formulation Development**: Prepare reagent solution with cryoprotectant matrix (6-10% trehalose, 2% PEG-8000, 0.5% BSA). Optimize pH (7.0-7.5) and ionic strength for target biomolecule.
2. **Pre-Freezing**: Dispense 50-100 μL per well (lateral flow) or 200 μL per vial. Freeze at -40°C for 4 hours (cooling rate: 1°C/min). Ensure complete solidification.
3. **Primary Drying**: Apply vacuum (<100 mTorr). Set shelf temperature to -20°C. Maintain for 16-24 hours until sublimation complete (monitored by pressure rise test). 4. **Secondary Drying**: Increase shelf temperature to 25°C gradually (0.5°C/min). Hold for 8-12 hours to remove bound water. Target residual moisture: 1-3%. 5. **Sealing and Testing**: Backfill with dry nitrogen. Seal immediately. Test rehydration time (<30 seconds) and activity recovery (>90% vs. fresh control).
## Troubleshooting
**Q: Cake collapse during lyophilization?**
A: Glass transition temperature (Tg’) exceeded during primary drying. Reduce shelf temperature or increase annealing step. Add higher Tg’ excipients (trehalose > sucrose).
**Q: Poor rehydration or incomplete dissolution?**
A: Residual moisture too low (<0.5%). Increase secondary drying temperature slightly. Add surfactant (0.01% Tween-20) to formulation. Ensure porous cake structure. **Q: Activity loss after lyophilization?** A: Protein denaturation during freezing. Add cryoprotectants (trehalose forms hydrogen bonds with protein). Optimize freezing rate (slow freezing damages proteins). ## Conclusion & OEM/ODM Services Lyophilized reagents enable room-temperature POCT distribution, critical for global market access. Due Bio has been developing lyophilized IVD reagents since 1987, with expertise in lateral flow strips, PCR cartridges, and CRISPR diagnostics. For lyophilization development or IVD Reagents OEM/ODM services, contact: **medtiger@foxmail.com** Visit: www.duebio.com