Profile: Whatman Ltd specializes in offering filtration components for manufacturers of medical devices and clinical diagnostic tests. We offer an extensive line of filter papers. The filters are tested for basic weight, thickness, air flow, and mechanical strength. In addition, special parameters such as particle retention, wicking rate, filtration performance, and surface characteristics can be measured as needed. Our cellulose filters are manufactured from quality cotton linters which have been treated to achieve a minimum alpha cellulose content of 98%. These cellulose filter papers are used for general filtration and exhibit particle retention levels down to 2.5 µm. We offer a wide choice of retention and flow rate combinations to suit numerous laboratory applications. The different groups of cellulose filters offer increasing degrees of purity, hardness, and chemical resistance. We manufacture chromatography products including chromatography paper, chromatography separation media, High Performance Liquid Chromatography (HPLC) columns, and Thin Layer Chromatography (TLC) plates. Our chromatography papers are the most widely used papers for chromatography worldwide. Our chromatography paper media are made from specially selected cotton cellulose. They are rigorously quality controlled for characteristics important to the chromatographer and to ensure uniformity within the grade. The chromatography paper product line includes standard cellulose and ion exchange grades. These are manufactured and tested specifically for chromatographic techniques. This ensures the wicking capability and uniformity of capillary action that are important in chemical separations.