Entrapment of a highly specific antiprogesterone antiserum using polysiloxane copolymers

Antiprogesterone antiserum was entrapped within a polysiloxane copolymer prepared from a 3:1 mixture of tetraethoxysilane and 3-aminopropyltriethoxysilane monomers. 400 microliters of this monomer mixture entrapped 70 mg of the 140 mg of immunoglobulins which were added, and the protein could not be washed from the highly stable copolymer which formed. Approximately half of the entrapped antiprogesterone antiserum was found to retain progesterone binding capacity with an apparent Ka equal to that of free antiserum in solution and was insensitive to effects of pH between 3 and 7. These preliminary observations and the unique chemistry of polysiloxane polymer formation suggest that such polymers may be useful in the entrapment of proteins for a variety of applications.