In modern cell biology and biomedical research, it is almost impossible to avoid them - cell sieves. What looks like a simple plastic part with filter mesh at first glance turns out to be a real all-rounder on closer inspection. Whether for sample preparation, cell separation or quality control, cell strainers are indispensable tools when it comes to clean, reproducible and cell-friendly filtration. But what exactly can you do with a cell strainer? And why are they actually called that?
What is a cell strainer - and why is it called that?
The term cell strainer describes laboratory analytical filter units used for the fractional separation of cells and cell aggregates based on their physical size. Essentially, these are mechanical sieve devices with precisely defined pore sizes—typically in the micrometer range, approximately 5 to 100 µm. These enable reproducible size selection of biological particles.
The name is a very functional combination:
- "Cell" refers to the biological cells found in tissue samples, cell cultures or blood.
- "Strainer" describes the physical principle: a porous structure that separates particles - in this case cells - according to size.
When filtering a cell solution, larger cell clumps, tissue remnants or unwanted cell types remain in the sieve, while smaller cells or particles can pass through. The term is therefore chosen for a similar function to that of a coffee filter or dust sieve - but in the context of cell biology.
Cell sieves are mainly used in cell biology, immunology, oncology and tissue diagnostics, where standardized and gentle cell separation while maintaining cell viability and integrity is crucial.
But what exactly can you do with a cell strainer?
Obtaining single cell suspensions from tissue samples
A classic application: You have enzymatically digested a piece of tissue - for example from the spleen, liver or a tumor - and want to produce a single-cell suspension. However, the result is often a heterogeneous mixture of cell clumps, tissue remnants and unusable material. A cell sieve with a mesh size of 70 or 100 µm, for example, helps you to retain larger particles and only let the cells through that you need for further analyses - for example for flow cytometry.
Cell size separation made easy
Not all cells are the same size - and this is exactly what you can take advantage of. Finely graduated sieves (e.g. 30 µm, 20 µm, 10 µm, 5 µm) can be used to divide a cell population into different fractions. For example, you can separate larger cell aggregates from individual cells or isolate specific cell types with certain sizes - an important step when working with stem cells or germ cells, for example.
Optimal preparation for flow cytometry
If you have ever sent a sample with aggregates through a FACS device, you know: Clogging or incorrect cell counts are inevitable. The solution? Sieve beforehand! A 20 µm filter reliably removes cell clumps and ensures that the detectors only really pick up individual cells. The result: cleaner data, better statistics, less hassle.
Clean and refresh cell culture
Cell strainers also provide valuable services in cell culture. You can use them to remove dead cells or debris without damaging the vital cells. When passing neuronal or haematopoietic cells, for example, rapid filtering helps to maintain the quality of the culture.
Also suitable for spheroids and organoids
In 3D cell culture, cell aggregates are specifically cultivated - so-called spheroids or organoids. These have a defined size that can be selected using cell sieves. For example, you can filter out structures that are too large or too small in order to cultivate a homogeneous population - ideal for reproducible experimental approaches.
Particle filtration in biological fluids
Cell strainers are not just for cells. They are also ideal for particle filtration in body fluids such as BAL (bronchoalveolar lavage), urine or plasma. For example, cell debris, mucus or large particles can be removed before the actual analysis takes place.
Why cell strainers are so popular
- Schnell & einfach in der Handhabung
- Schonend für die Zellen
- Hohe Reproduzierbarkeit
- In verschiedenen Maschenweiten - von 5 bis 2.000 µm - erhältlich
- In verschiedenen Größen verfügbar
- Kompatibel mit Standard-Labware (z. B. 15 oder 50 mL Röhrchen)
Conclusion: Cell Strainer are small but crucial
Cell strainer may seem inconspicuous at first glance - but anyone who works with living cells knows that the quality of sample preparation often determines the success of the entire experiment. Whether for single cell analysis, cell culture, diagnostics or 3D cell models - cell sieves are the invisible helpers that ensure clean results in the background.