Filter paper is thick (0.73 mm) and highly absorbent. 1.0 µm retention efficiency. 5.5 ml/sec. flow rate. Loading capacity is very high. Water absorption 275 ml/m2. The best wet strength. Used for collecting biochemical polymers, e.g. nucleic acids, proteins, precipitated by denaturation. For collection of gases absorbed onto solid particles. Used for sampling of biological fluids. (For cost savings, see Ahlstrom equivalent, 461-200-02 Series)