Syringe Pumps in Cell Analysis Techniques

Syringe Pump Flow Rate

A syringe pump is used in controlled delivery of liquids because it offers a high level of accuracy and reliability. Cell analysis require precise flow control, which makes syringe pumps highly suitable thanks to their ability to deliver micro- and nanolitre volumes. Whether syringe pumps are implemented in microfluidics or single-cell analysis, they ensure consistency across different replicates of an experiment and preserve sample integrity.

Key benefits of using syringe pumps for accurate cell analysis

Precision and reproducibility: Syringe pumps enable consistent flow rates, which is critical for uniform delivery of reagents and cells.

Gentle handling: Syringe pumps help avoid mechanical damage to the cells. This ensures that they retain their natural morphology.

Broadened application range

Efficiency: Syringe pump-driven single-cell analysis reduces the time needed for analysis, improving throughput without sacrificing sensitivity.

Syringe pumps in single-cell analysis

Single-cell analysis is a vital tool in biological research that requires precise sample metering. It helps researchers to understand biological processes at individual cell level. In these experiments, it is important to deliver the sample precisely and gently, which helps prevent the damage of the cells. This is a common issue with peristaltic pumps, which can crush or distort cells due to the mechanical forces applied in the tubing. Therefore, it is recommended to use a syringe pump which offers more controlled mechanism that maintains the cellular viability and integrity.

While syringe pumps are not as cost-effective as peristaltic pumps, their precision, sterility and gentleness justify the cost. They are often used in biological assays that require accurate flow control and reproducibility rather than high flow rates.

Flow cytometry

Flow cytometry is a useful technique for differentiating and characterising various cell populations, including bacteria and human cells. In large-scale studies, fluorescent and biochemical labels are usually implemented. However, the specific properties of cells, such as size and charge, can be studied using syringe pumps when labelling is not available.

There are two known systems used for the injection of samples into the flow chamber. The most common system used is the pressure differential system. The rate of sample flow is determined by the pressure difference and by fluid resistance of the sample tubing leading from the vial to the nozzle. While this method benefits from the sheath fluid flushing the sample tubing after the vial is removed, there is no simple relationship between the pressure difference and the flow rate. This means that there is no way to inject the sample at a predetermined rate or to measure the rate with high precision. The result is that the cell concentration of the sample cannot be determined in a different way than mixing a known concentration into the sample. The other system, volumetric sample injection, offers a solution to this by implementing a syringe pump. By being run at calibrated rates, syringe pumps enable the calculation of the cell concentration within a sample in real time. On top of that, the rate of the flow can vary, ranging from high to very low rates. However, one disadvantage of this technique is the flushing process, as it is more complicated and time consuming than the pressure differential system.

Flow cytometry with syringe pump

All in all, the volumetric sample injection system combines highly precise injection rates with efficient flushing and low carryover. This means that using a syringe pump for flow cytometry is more beneficial for the researcher, providing more control over the injection as well as allowing more detailed information on the cell concentration within a sample.

Impedance-based cell analysis

Cell's impedance is the resistance to alternating current which is studied through impedance spectroscopy. This technique measures the changes in cellular impedance to identify and classify them. Syringe pumps are essential here, ensuring a smooth, precise flow that preserves the integrity of the cell samples and enables reliable, reproducible results.

Impedance analysis not only allows the identification of cells, but also highlights the theoretical differences between cells. This enables researchers to establish models, basis of which serve to simplify the identification of cells. The main factor for cellular differentiation is the change in the membrane of each cell during the analysis. A study investigating HeLa cells using the impedance analysis along with a syringe pump highlighted how the experimental results and theoretical models agreed with each other. The results provide an enhanced value of the impedance technique for cell differentiation.

Additionally, impedance-based cell analysis using a syringe pump is cheaper when compared to classical tagged techniques such as fluorescence or chemical labelling.

Microfluidic platforms

By offering high precision alternative to traditional research methods, the lab-on-a-chip paradigm started a revolution in biochemical research. The chips consist of a network of microscopic channels, designed to combine small amounts of experimental liquid with adhering material. These platforms require a precise, reproducible administration of liquids, which makes syringe pumps the perfect fit.

The most common biochemistry research in which microfluidic platforms have been implemented is the study of DNA. DNA chips or microarrays consist of compilations of DNA fragments attached to a solid surface. They have been designed to study genotypisation of multiple regions or measuring expression levels of multiple genes.

Cell culture is an important part of biological research and pharmaceutical development. To ensure a consistent growth of the cells in vitro, it is important to consider several factors, such as temperature, pH and nutrient levels. Implementing microfluidics into cell culture provides control over these factors as it allows the manipulation of fluid at a microscale. One key element in microfluidic cell culture is the precise regulation of fluid flow over the cultured cells. As microfluidic systems allow continuous perfusion, they are becoming the standard for cell cultures. This is because static culture models fail to mimic the dynamic environment cells encounter in vivo. The continuous flow of media, reagents or solutions is provided by the use of a syringe pump. This helps ensure that the microenvironment remains stable and physiologically relevant.

Applications of microfluidic platforms

Live cell imaging and analysis
Micro physiological systems, such as organ-on-a-chip
Barrier models
Cell rolling and adhesion assays
Shear stress studies
Molecular transport
Drug screening
Behavioural and developmental studies

Mass spectrometry

Mass spectrometry is an analytical tool often used in biochemical research. It enables researchers to identify unknown compounds in a sample, such as biomolecules or protein complexes. Through measuring the mass-to-charge ratio of molecules, it specifies their molecular masses. This relies on ionizing samples and the easiest form of this technique is direct infusion mass spectrometry. As it is necessary to have high precision administration of samples in this technique, syringe pumps are a great fit thanks to their design for high precision and steady flow dosing purposes.

High performance liquid chromatography

High performance liquid chromatography is an analytical technique often used in biochemical research. Using this method, researchers are able to separate and identify very low concentrations of analytes in a sample. The principle of the technique lies in the mobile phase of a sample, which is pumped into a chromatography column at high pressure. Once it is through, it interacts with molecules that are in a stationary phase. Using a syringe pump for the injections ensures accurate and reproducible results as it provides pulseless continuous flow rates.

Learn More

What is Microfluidics?

Microfluidics is a ground-breaking field of research focused on the development of fluid-processing experiments at the microscale. Imagine a circuit board, but for liquids: microfluidic devices, often referred to as "chips", are patterned with minuscule channels and ducts through which liquids flow. In these compact and constricted conditions, liquid exhibit unique behaviours that can be harnessed for rapid and high-throughput results.

Contributors

Written by

Linda Vidova

Scientific Writer