Rapid Pathogen Detection Using Due Bio Microfluidic PCR Cartridge System

# Rapid Pathogen Detection Using Due Bio Microfluidic PCR Cartridge System

## Abstract

Conventional PCR workflows require bulky thermal cyclers, extensive pipetting, and prolonged turnaround times—limiting deployment in point-of-care and resource-limited settings. Due Bio’s Microfluidic PCR Cartridge System integrates sample preparation, amplification, and detection in a closed, portable platform that delivers results in under 60 minutes. This application note outlines a streamlined protocol for detecting bacterial and viral pathogens using Due Bio’s 2-step rapid cycling microfluidic technology.

## Introduction

Polymerase Chain Reaction (PCR) remains the gold standard for nucleic acid detection, yet traditional implementations demand sophisticated laboratory infrastructure. Point-of-Care Testing (POCT) requires miniaturization, simplified workflows, and rapid turnaround—challenges that microfluidic technology uniquely addresses.

Due Bio’s Microfluidic PCR Cartridge leverages advanced chip design and optimized thermal profiles to achieve 2-step rapid cycling (95°C/55°C), reducing amplification time by 40% compared to conventional 3-step protocols. The closed-cartridge format minimizes contamination risk while enabling deployment in field hospitals, veterinary clinics, and decentralized testing laboratories.

As a POCT manufacturer since 1987, Due Bio combines decades of IVD expertise with cutting-edge microfluidics to deliver accessible molecular diagnostics.

## Materials Required

– **Due Bio Microfluidic PCR Cartridge** (8-channel or 16-channel format)
– **Due Bio IVD Reagents** (Lyophilized PCR master mix, target-specific primers/probes)
– Due Bio Cool Flash or Star Flash Nucleic Acid Release Reagent
– Sample types: whole blood, nasopharyngeal swabs, saliva, or environmental samples
– Due Bio LF-detect Universal or Cas12/13 strips (for endpoint detection)
– Portable thermal cycler or Due Bio handheld reader
– Micropipettes (10 μL and 100 μL)
– Timer or stopwatch

*Note: Cartridges are supplied ready-to-use with lyophilized reagents. Store at room temperature (18–28°C). Reagents should be stored at –20°C. Shelf life: 18 months.*

## Step-by-Step Protocol

### 1. Sample Preparation

Add 100 μL of liquid sample (or swab eluate in transport medium) to a Due Bio Cool Flash Nucleic Acid Release tube. Mix by vortexing for 10 seconds. Incubate at room temperature for 5 minutes to lyse cells and release nucleic acids. No centrifugation, filtration, or purification required.

### 2. Cartridge Loading

Using a 10 μL pipette, transfer 5 μL of lysed sample into each reaction chamber of the microfluidic cartridge. The lyophilized PCR reagents (primers, probes, polymerase, dNTPs, buffer) are pre-loaded during manufacturing and rehydrate upon sample addition. Seal the cartridge with the provided adhesive film to prevent evaporation.

### 3. Amplification

Insert the loaded cartridge into the thermal cycler or handheld reader. Run the 2-step rapid cycling protocol:
– 95°C for 3 minutes (initial denaturation and polymerase activation)
– 45 cycles of: 95°C (5 sec) / 55°C (20 sec, data acquisition)
– Total run time: 25–30 minutes

The microfluidic design ensures uniform heat transfer and consistent amplification across all channels. The portable format enables battery-powered operation in field settings.

### 4. Detection

**For fluorescence-based readers**: Real-time amplification curves are displayed automatically on the device screen or connected mobile app. Ct values are calculated and interpreted.

**For lateral flow detection**: Transfer 5 μL of amplified product to a Due Bio LF-detect Universal strip. Add to sample well and read at 15 minutes.

### 5. Result Interpretation

**Fluorescence detection**:
– **Positive**: Amplification curve crosses threshold (Ct < 35) - **Negative**: No amplification or Ct ≥ 35 - **Invalid**: No amplification in positive control channel **Lateral flow detection**: - **Positive**: Both control (C) and test (T) lines visible - **Negative**: Control line (C) only - **Invalid**: No control line ## Troubleshooting ### Q: No amplification in positive control. **A**: Verify reagent storage conditions and expiration date. Lyophilized reagents are stable at room temperature but should be protected from humidity. Ensure thermal cycler is calibrated. Try a new cartridge from a different lot. Contact Due Bio technical support for lot-specific QC certificates. ### Q: High background or non-specific amplification. **A**: Annealing temperature may be too low. Increase the 55°C step to 58–60°C. Ensure primers are designed with Tm between 58–62°C. Reduce cycle number to 40 cycles if background persists. ### Q: Weak or inconsistent signal across channels. **A**: Ensure sample is evenly distributed and cartridge is properly sealed. Avoid introducing air bubbles during loading. Centrifuge cartridge briefly (1000 × g, 1 min) before amplification if needed. --- ## Conclusion & OEM/ODM Call-to-Action Due Bio's Microfluidic PCR Cartridge System brings laboratory-grade molecular testing to the point of care. The closed, portable format reduces contamination risk while 2-step rapid cycling delivers results in under 60 minutes. **Established in 1987**, Due Bio is a global POCT manufacturer committed to advancing accessible molecular diagnostics. Beyond our standard products, we provide comprehensive **IVD Reagents OEM/ODM services** including custom assay development, cartridge design, private labeling, and regulatory support for CE/FDA submission. Whether you're developing an infectious disease panel, a veterinary diagnostic test, or an environmental monitoring assay, Due Bio's technical team can support your project from prototype to commercialization. **Contact us today**: medtiger@foxmail.com --- *For research use only. Not for diagnostic procedures unless validated and approved according to local regulations.*

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