In the U. S. the burden remains on the examiner throughout prosecution to raise a prima facie case for rejection, but in the EPO and the JPO the burden is ultimately on the applicant to demonstrate enablement. [...] The EPO requires a precise definition of the fragment/probe length or of the part of the amino acid sequence of the encoded protein or peptide. [...] However, though the JPO and the EPO find that the burden of proof (the burden of persuasion) is finally on the applicant throughout prosecution, the USPTO always has the burden of proving that the specification is not enabled. [...] The assessments under the guidelines are made from the viewpoint of one of ordinary skill in the art in light of the disclosure and other evidence of record. [...] The Written Description Guidelines restate that the disclosure must demonstrate to one of ordinary skill in the art that as of the filing date the applicant had possession of the claimed invention.