Patent ID: 7504204

Claim:
An immunoassay method useful for quantitating transmissible spongiform encephalopathy (TSE) protein in a biological sample, comprising the steps of: a) preparing a relevant biological sample for a Western blot assay, including preparing buffered dilutions of the sample using a physiologically compatible buffer and treating the buffered dilutions with proteinase-K; b) concentrating the buffered dilutions to form concentrated proteinase-K samples; c) preparing a spiked control sample comprising TSE protein for the Western blot assay, using a physiological compatible buffer and treating the spiked control sample with proteinase-K; d) performing the Western blot assay for TSE protein on the concentrated proteinase-K samples and the control sample; and e) quantitating the TSE protein results by quantifying the results of the Western blot assay by (i) determining the number of immunoreactive positions that contain a signal attributable to the presence of TSE protein in the relevant biological sample; (ii) determining the number of immunoreactive positions that contain a signal attributable to the presence of TSE protein in the control sample; and (iii) approximating the amount of TSE protein present in the relevant biological sample to the limits of detection by comparison to results obtained for the control sample, wherein the signal attributable to the presence of TSE protein is visualized using a chemiluminescent technique, and wherein the method can detect as low as 5 pg of TSE protein in the relevant biological sample.