Test devices, systems, and test kits are provided for
rapid detection with high specificity of the pathogenic form of prion
protein responsible for neurodegenerative diseases affecting humans and animals, such as
transmissible spongiform encephalopathy in bovine, sheep, and cats. The present invention is also useful for testing animal feedstock made from animal parts. Results are available in from about 0.5 to about 20 minutes and preferably from about 5 to about 10 minutes after the sample is introduced to the device and
system. The devices, systems, and test kits employ proteinase-K to remove noninfectious prion
protein from a biological sample, so that the sample may be analyzed by immunochromatography to determine the presence and concentration of pathogenic prion
protein. Because the proteinase-K is immobilized on a
solid support for in-situ removal of interfering components, the present invention obviates the need for subsequent extraction of the desired
analyte. All aspects of the present invention are suitable for quantifying the minimal detectable amount of pathogenic prion protein in a biological sample. Moreover, the simplicity of
sample preparation makes the present invention suitable for use in the field.