Abstract
The development of mechanical supports for biochemically active compounds serving as immunochemical sensors has been the goal of many studies. A new compound in the form of gel fiberglass (GFG) membranes was recently developed as an example of such supports. These membranes prepared from glass fibers covered with oxysilanes to create a matrix 'gel fiberglass' (R. Zusman, USA Patent #08/112,087, 1993) were used to prepare affinity chromatography columns for the isolation of soluble p53 protein from the serum of cancer patients. A thin layer of protein, trapped in gel glass during its preparation, was deposited on a lattice of glass fibers. Derivatization of the support eliminated nonspecific adsorption of proteins. Under such conditions, external agents percolating through a membrane may contact a maximum number of protein molecules trapped in the gel glass. The membranes are very stable, and can be stored in dry conditions for several months at room temperature. Affinity chromatography columns were prepared from the GFG membranes and used to isolate various proteins, including tumor-associated antigens (TAA). The capacity of the columns was calculated as the amount of protein (mg ml(-1)) isolated from TAA-containing solution, and amounted to up to 9 mg ml(-1) of serum in colon cancer patients. The cytoplasmic p53 protein was one of the main components of TAA isolated in our experiments. Its concentration was determined by HPLC. This protein was isolated from the serum of cancer patients in the highest concentration yet reported, up to 5 mg ml(-1). The described method allows an easy and highly effective isolation of TAA and can be used for important goals including cancer diagnosis.
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