Proteins are highly delicate molecules in various biological substances, ranging from microorganism levels to those of human beings. There are millions of varieties of proteins of which only a fraction has been revealed to mankind. Many more are being researched regarding their properties. If these proteins are discovered, then they can be utilised in different ways to cure diseases, help transport macromolecules and at best allow the scientists to understand the functioning of various exogenous and endogenous substances. Till recently, it had been quite difficult to study the properties of these molecules, but for the observation through highly advanced techniques.

Fine measuring instruments are being designed to carry out various diagnostic and therapeutic procedures involved in research activities. These researches are directed towards study of various biological micro and macro molecules. Among these, proteins are the most extensively studied elements, which require good scientific knowledge. It has been presently realised that biologically derived polymers of dextran and agarose are highly efficient in filtering proteinaceous substances from a mixture of fluids or microscopic elements.

€ Good solutions of filtration of protein containing fluids - Due to the realisation of using biological substances in identifying and differentiating proteins, the beaded forms are supposedly of good value. Bead forms are suitable because they occupy less space but provide more surface area for filtering process. Since the agarose bead is used in protein filtration and chromatography, many scientific experiments are done after passage of the fluids through the columns containing these beads. Agarose in particular offers good substrates for filtration because of the ability to filter out large sized particles and allow only smaller protein materials to pass through.

€ Chemical properties of advantage in biological experiments - Besides the size and shape, the chemical nature of dextran and agarose is such that it offers a non-fouling surface for filtration. Even when used for long period, these beads do not give out bad odour. Chemically they are also quite stable, without reacting with any kind of proteins and even resist high variations in pH and ionic phases. In mostly affinity applications, the dextran bead is a good option because it is chemically stable.

€ Variations in sizes to bring protein filtration - Availability of the agarose bead in different sizes is also another advantage of this kind of filtration system. They are sometimes designed especially for proteins, whose sizes are known. If these proteins are present, they can pass through, without allowing other molecules to be filtered. This versatility and possibility to use variations has given much popularity to agarose and dextran usage.

Many scientists are utilising the dextran bead for filtering proteins for testing. They can not only tolerate variations in medium, but can also be cross linked in different modalities to use in separate settings. As resins, these beads provide the best platforms in various research activities and have impressed many researchers with their properties. Nowadays in many of the experiments and research works, the bead forms of dextran and agarose have been specially designed for their usage in filtration of proteins and other similar biological macro molecules.