Filtration

FILTRATION

  • Filtration is the best method for sterilization of heat labile substances like proteins,enzymes etc. Different types of filters are used.
  • The commonly used ones are nitrocellulose membranes with pore diameters of 0.22 or 0.45 um, asbestos sheet or porcelain. The sterilization flask is usually attached to a negative pressure pump.
    • Berkfield filter: In this filters made up of diatomaceous earth are used. They are in the shape of a candle. Such candles are placed inside specially designed goblet vessel. This filtration assembly is placed over filtration flask and medium filtered by providing negative pressure.
    • Chamberland filter: These filters are like Berkfield filters but have different grades of candles.
    • Ultrafilters: In this nitrocellulose membranes are used. They are placed over a porous disc. The assembly is placed over a filtration flask and medium filtered by applying negative pressure.
    • Seitz filter: In this special EKS sheets made of asbestos are used.
Last modified: Saturday, 24 September 2011, 4:26 AM