Low Cost Three-Dimensional Programmed Mini-Pump Used in PCR

Area of Science:

• Biomedical Engineering
• Laboratory Automation
• Molecular Diagnostics

Background:

• Programmed mini-pumps are crucial for precise liquid transport in chemistry, biology, and medicine.
• Existing automatic pipetting pumps are often expensive and complex for routine laboratory use.
• Accurate liquid handling is essential for molecular diagnostic techniques like PCR, including COVID-19 detection.

Purpose of the Study:

• To design and assemble a cost-effective, three-dimensional programmed mini-pump using common laboratory components.
• To evaluate the accuracy and reproducibility of the custom-built mini-pump for trace liquid measurements.
• To compare the performance of the programmed mini-pump against manual pipetting in quantitative PCR (qPCR) assays.

Main Methods:

• Assembly of a three-dimensional programmed mini-pump utilizing a PLC controller, motor, and microinjector.
• Weighting calibration before and after pipetting operations to determine accuracy at volumes of 10 μL, 2 μL, and 1 μL.
• Comparative qPCR experiments using ORF1ab and pGEM-3Zf (+) genes to assess reproducibility against manual pipetting.

Main Results:

• The custom mini-pump achieved low error rates: 0.2% at 10 μL, 1.8% at 2 μL, and 5.6% at 1 μL.
• The programmed mini-pump exhibited stronger reproducibility in qPCR assays compared to manual pipetting.
• Statistical analysis showed no significant difference (p > 0.05) between the pump and manual methods, indicating comparable performance with enhanced consistency.

Conclusions:

• A functional, low-cost, three-dimensional programmed mini-pump was successfully designed and assembled.
• The developed mini-pump offers improved reproducibility for trace liquid measurements, particularly in qPCR applications.
• This innovation provides a foundation for accessible and efficient automated liquid handling in various scientific fields.