Track etched membranes
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Track etched membranes (TEMs) are extremely thin yet highly controlled membranes. Traditionally, TEMs have been used for sample filtration before critical applications such as HPLC.
Broad Applicability Across Applications
The properties that make TEMs ideal for applications like filtration are becoming increasingly important for diagnostic tests.
Tightly controlled filtration properties allow you to capture cells of a specific pore size on the membrane surface. Enables cells to be detected in a clearer environment, yielding improved accuracy.
Particle capture and latex agglutination.
The distinct pore size of TEMs enables the capture of particles of known sizes. Now you can construct assays in which capture reagents are bound to a latex bead (i.e., bead capture assays) or the antigen causes particle agglutination whereby the agglutinated clusters are captured on the membrane surface.
With biosensors, it is important to control liquid migration rates onto the sensor and prevent potential contaminants from reaching the sensor surface. The flow properties of a TEM can be chosen to yield the correct flow of liquids or gases through the membrane in order to obtain optimal sensitivity. It is also possible to modify surface properties so that membranes will serve as barriers to contaminants.
Erythrocyte deformability testing.
Since healthy erythrocytes are highly flexible, they will readily change shape to pass through small openings. In several haemopathies, the ability of the cell to flex is reduced to the extent that it can no longer pass through a small aperture. When TEMs are used as a barrier to abnormal erythrocytes, it is possible to test for disease states.
In short, the degree of control that is possible in TEM manufacturing not only gives rise to a number of applications in which standard materials would fail, but also makes process validation and regulatory control easier and more intuitive.
Features and Benefits
- Defined pore size.
The claimed nominal pore size is the largest pore size present in the membrane. The intra-lot variation in pore size is typically between two and three percent.
- Biologically inert.
Since TEMs are manufactured from PC, the possibilities of assay interference are remote.
- Control of flow rate.
TEMs are available with hydrophobic or hydrophilic surfaces in a range of pore sizes and pore densities. The flow rate of liquid through the membrane can therefore be tightly controlled.