Abstract: A tumor associated protein has been discovered to exhibit immunoreactivity to human monoclonal antibody L92. A ten amino acid peptide segment of the protein and a fourteen amino acid peptide which contains the ten amino acid peptide has also been isolated and exhibits immunoreactivity to the same antibody. Using truncated fusion proteins, the minimum recognition site for antibody binding was determined to be four amino acids. Also disclosed are polypeptide compositions against human tumors that includes the polypeptides or protein of the present disclosure, as well as antibodies reactive with these polypeptides that may be employed directly for treatment or diagnosis. A certain embodiment of the present invention is also the DNA sequence encoding the ten amino acid peptide and the DNA encoding the fourteen amino acid peptide which also exhibits immunoreactivity to human monoclonal antibody L92 and cytotoxic T cells.

Abstract: The present invention provides for the screening of candidate substances to identify active compounds that inhibit multidrug resistance (MDR). The expression of glucosylceramides has been determined to be a marker of MDR. By measuring glucosylceramide expression in cells exhibiting MDR, and the reduction in glucosylceramide levels in the presence of a candidate substance, the present invention provides for the identification of MDR inhibitory compounds.

Abstract: A recombinant cell line expressing a polypeptide with the amino acid sequence -Gln-Asp-Leu-Thr-Met-Lys-Tyr-Gln-Ile- has been isolated. The cell line was described as a recombinant E. coli strain. Isolated purified polypeptide include 10 or less amino acid sequences to a length of less than 100 amino acid sequences. The polypeptide is further defined as including the amino acid sequence of beta-galactosidase or glutathione-S-transferase.

Abstract: A tumor associated protein has been discovered to exhibit immunoreactivity to human monoclonal antibody L92. A ten amino acid peptide segment of the protein and a fourteen amino acid peptide which contains the ten amino acid peptide has also been isolated and exhibits immunoreactivity to the same antibody. Using truncated fusion proteins, the minimum recognition site for antibody binding was determined to be four amino acids. Also disclosed are polypeptide compositions against human tumors that includes the polypeptides or protein of the present disclosure, as well as antibodies reactive with these polypeptides that may be employed directly for treatment or diagnosis. A certain embodiment of the present invention is also the DNA sequence encoding the ten amino acid peptide and the DNA encoding the fourteen amino acid peptide which also exhibits immunoreactivity to human monoclonal antibody L92 and cytotoxic T cells.

Abstract: A method for preparing serum depleted of IgG to be used in the production of IgG monoclonal antibodies is disclosed. Animal serum is contacted with protein G or protein A prior to addition to base media to obtain a superior cell culture medium depleted of serum derived IgG antibodies. Included in the disclosure are improved media preparations for cell culture of antibody producing cells and incorporating the antibody depleted serum and improved methods of producing the antibodies.