Method of preparing cow brain homogenate

摘要

An assay method is disclosed which isolates and detects the presence of a disease related conformation of a protein (e.g., PrP^Sc) present in a sample also containing the non-disease related conformation of the protein (e.g., PrP^Sc). The sample is treated (e.g., contacted with protease) in a manner which hydrolyzes the disease related conformation and not the non-disease related conformation. The treated sample is contacted with a binding partner (e.g., a labeled antibody which binds PrP^Sc) and the occurrence of binding provides and indication that PrP^Sc is present. Alternatively the PrP^Sc of the treated sample is denatured (e.g., contacted with guanadine) or unfolded. The unfolded PrP^Sc is contacted with a binding partner and the occurrence of binding indicates the presence of PrP^Sc in the sample. In another embodiment, PrP^Sc and PrP^C are reacted with a labeled antibody that binds both conformations and a conformation that binds only the disease related conformation, and the presence of the disease related conformation is determined by comparing the two.