Objective:

To evaluate the performance of the pocket-size fluorimeter VPodDuo in comparison to larger laboratory instruments across several rapid molecular tests.

Approach:

• Testing Methods: The VPodDuo was evaluated using various molecular assays including reverse transcription loop-mediated isothermal amplification, recombinase polymerase amplification, CRISPR-based assays, and a nonenzymatic amplification method.
• Targets Assessed: The tests covered nucleic acid targets associated with Zika virus, methicillin-susceptible Staphylococcus aureus, human immunodeficiency virus, and lung cancer.
• Performance Metrics: Assay reactions lasted approximately 10 minutes, and detection limits were compared with those of laboratory instruments.

Key Findings:

• For Zika virus, both VPodDuo and QuantStudio achieved a detection limit of 10,000 copies/µL.
• For methicillin-susceptible S. aureus, detection limits were 100 copies/µL for VPodDuo and 10 copies/µL for QuantStudio.
• In CRISPR-based testing, VPodDuo identified HIV at approximately 7 pM, compared to 8 pM using a laboratory microplate reader.
• The VPodDuo identified the L858R EGFR mutation at approximately 29 pM, compared to 47 pM using a laboratory reader.
• Both VPodDuo and a commercial Qubit fluorimeter achieved a detection limit of 500 pM for miR-375-3p.

Interpretation:

The VPodDuo demonstrated comparable performance to larger laboratory instruments for various molecular assays in controlled conditions.

Limitations:

• The study assessed analytical performance rather than clinical diagnostic accuracy.
• Testing was conducted on targets diluted in buffer rather than patient specimens.
• Most assays required separate heating equipment as the instrument did not contain a heating block.

Conclusion:

Further studies using clinical specimens are needed to evaluate sample preparation, reproducibility, calibration, and performance under varied environmental conditions.

Sources:

• IEEE Sensors Journal