Filter pads

When it comes to lateral filtration for plasma separation, the key physical characteristics of fiber-based materials that need to be considered to get good and sufficient quantities of plasma are the absorption capacity linked to the thickness of the plasma separation pad, the red blood cell retention capacity and the overall dimension of the pad for the sample volume.

For a fixed volume of blood, as thickness of blood separation pads increases, amount of recovered plasma decreases. However, by using appropriate pads dimensions and a specific chemical treatment, significant improvement in plasma recovery can be achieved.

If the correct fibrous components are not chosen, hemolysis or rupturing of the red blood cells can occur. Hemolysis of any type should be limited within the diagnostic tests, as the rupture of the cells leads to the release of hemoglobin molecules, causing the serum or plasma to have a pink to red color, thus making the readout difficult to judge.

Leakage of the cells content along the membrane can also cause problems such as low sensitivity, selectivity and inaccurate results. One of the main reasons causing hemolysis can be the use of an inappropriate type of glass separator pads, especially the ones with small diameter glass fibers.