Both filters and papers used in research are key to filtration and separation techniques. Many dedicated variants exist to fit the requirements of defined processes and experiments.
Filters separate components in a solution or mixture, with the aim of purifying the filtrate for downstream applications. Syringe filters are very popular; for example, they are used to remove contaminants from nutrients such as growth factors during culture media preparation. There are also gas-specific filters to remove moisture, pollution and airborne particles.
Papers have a variety of functions depending on their design. Whatman is one of the most popular brands used. Filter papers act as a semi-permeable barrier and are useful for precipitate recovery during filtration. They can vary in their grade, extending from coarse to fine filtration. Chromatography paper, often made of cellulose, is used for analytical separation of compounds, optical/radiometric scanning or electrophoresis, depending on the grade quality.