Species cross reactivity not tested 

2°C to 8°C  (≤ 30 days)

For long-term storage (> 30 days), aliquot and store at ≤ –20°C. Avoid repeated freeze-thaw.

For Research Use Only. Not for use in diagnostic procedures

Highly purified human Factor I was isolated from normal serum and used to immunize goats. The Anti-human Factor I was tested against normal human plasma by double immunodiffusion, one-dimensional immunoelectrophoresis, quantitative radial immunodiffusion, and quantitative rocket immunoelectrophoresis. The antisera was determined to be monospecific for Factor I at varying concentrations.

Factor I is a serine protease which circulates in the plasma and is synthesized primarily in the liver. This glycoprotein has a total approximate molecular weight of 88 kD. It is composed of two chains (50 kD and 38 kD) that are linked together by a disulfide bond. The concentration of this protein in normal plasma is approximately 34 µg/mL. In the complement system, Factor I cleaves and inactivates C3b, C4b, and modified forms of C3 and C4. This cleavage can only happen in the presence of protein cofactors such as Factor H, CR1, and C4 binding protein (C4BP). Factor I is only considered to be active in the presence of these cofactors.

Applications of the Factor I polyclonal antisera have been evaluated by various research facilities, and include Western Blot, 1, 2 ELISA. 3