The invention relates to an antibody, antibody fragment or derivative thereof which specifically recognizes a prion protein and which comprises a complementarity determining region (CDR), a retro-inverso D-peptide of said CDR and/or an anti-idiotypic antibody, antibody fragment or derivative thereof which recognizes said CDR. The invention further concerns a nucleic acid molecule encoding said antibody, antibody fragment or derivative thereof as well as a method for generating an antibody, antibody fragment or derivative thereof that specifically recognizes a prion protein, wherein an antibody that recognizes a specific domain of the prion protein is generated, an antigen-specific amino acid sequence is isolated from said antibody, and an anti-idiotypic antibody, antibody fragment or derivative thereof, which recognizes said antigen-specific amino acid sequence, is generated.