Selecting a Pump for Hematology Analyzers

The Importance of Selecting the Right Pump for Hematology Analyzers

In the design and optimization of hematology analyzers, fluid handling is one of the most critical considerations. These instruments depend on precise, repeatable liquid movements. Whether aspirating whole blood, diluting reagents, transferring waste, or to ensure accurate diagnostic results, selecting the wrong pump can lead to unreliable counts, maintenance issues, and increased operational costs.

For manufacturers and system designer engineers, the challenge is to find a pump technology that delivers exceptional precision, chemical compatibility, and long-term reliability. Among the options available (peristaltic, diaphragm, gear, and syringe pumps) rotating and reciprocating piston pumps consistently stand out as the optimal choice for hematology applications.

The Problem: Precision and Longevity in a Demanding Environment

Hematology analyzers handle small sample volumes and demand extremely accurate dosing, often down to microliter levels, with consistent performance over tens of millions of cycles. The pumps used in these systems must also tolerate potentially abrasive fluids and a variety of reagents, all without compromising volumetric accuracy.

Common issues with less suitable pump types include:

• Drift in flow rate over time due to tubing wear (peristaltic)
• Inconsistent stroke volume from check valve leakage or diaphragm fatigue
• Maintenance-heavy designs that require frequent recalibration or replacement

The Solution: Fluid Metering Rotating and Reciprocating Piston Pumps

Rotating and reciprocating piston pumps solve many of the challenges that other pump technologies struggle to overcome. These pumps operate using a piston-driven displacement mechanism that provides highly accurate, repeatable volume control with minimal internal leakage.

Key Advantages:

• Exceptional Accuracy and Repeatability

Piston pumps provide precise volumetric displacement with accuracy down to single-digit microliters. This is critical for hematology analyzers where sample integrity and test consistency are non-negotiable.

• Robust Chemical Compatibility

Pumps constructed with chemically inert materials (e.g., ceramic pistons, fluoropolymer seals) can withstand exposure to various chemicals and cleaning solutions.

• Long Life and Low Maintenance

With fewer moving parts and wear-resistant materials, piston pumps often exceed 90 million cycles with minimal maintenance, an ideal match for high-throughput analyzers.

• Compact, Configurable Designs

Piston pumps can be miniaturized for integration into tight instrument footprints and customized for specific flow rates or stroke volumes depending on system requirements.

In a typical 3-part or 5-part differential hematology analyzer, piston pumps can handle a wide range of operations. Such as precise sample aspiration from capillary or venous tubes, accurate mixing and dilution of reagents and samples, timed delivery of lysing or staining agents, and consistent waste disposal with minimized carryover

Unlike peristaltic systems, which can require regular tubing replacement and recalibration, piston pumps offer stable, repeatable performance, reducing downtime and increasing analyzer throughput.

Conclusion: A Smarter Investment for High-Performance Diagnostics

In the evolving landscape of in-vitro diagnostics, analyzer reliability and accuracy are more important than ever. Fluid Metering pumps provide the performance, durability, and fluid control precision required by modern hematology systems. Whether you’re designing a new analyzer or optimizing an existing platform, Fluid Metering pump technologies offer a smart, scalable, and long-term solution, ensuring every drop counts.