The invention provides an analytical process for analysing the presence of at least one aggregated conformation prion protein in a sample of body fluid or a sample of tissue and uses the dependency of the amplification of the aggregated conformation on the shear-force intensity applied to the native conformation prion protein, which is also dependent on the specific seed present in the admixture with native conformation prion protein, for specifically analysing for the presence of an aggregated conformation prion protein in the sample. The process of the invention contains the step of determining the content of aggregated conformation prion protein generated in admixture with the sample to be analysed using one shear-force intensity, preferably using least at two different shear-force intensities and the step of comparing data on these contents of generated prion protein having an aggregated conformation with data on the content of aggregated prion protein that is pre-determined, each at the same shear-force intensity for a mixture of the same native conformation prion protein with a reference sample as a seed.