A fundamental requirement of patent law is that the details of an invention must be fully
disclosed to the public. For disclosure to be adequate, an invention must be described in
sufficient detail to permit a person skilled in the art to repeat the effect of the invention: in
other words, the disclosure should enable the average expert with access to the appropriate
facilities to reproduce the invention for himself. Disclosure is normally achieved by means of
a written description supplemented where necessary by drawings. However, inventions
involving the use of new microorganisms (i.e., those not available to the public) present
problems of disclosure in that repeatability often cannot be ensured by means of a written
description alone. In the case of an organism isolated from soil, for instance, and perhaps
“improved” by mutation and further selection, it would be virtually impossible to describe the
strain and its selection sufficiently to guarantee another person obtaining the same strain from
soil himself. In such a case, the microorganism itself might be considered to be an essential
part of the disclosure. Moreover, if the microorganism was not generally available to the
public, the written disclosure of the invention might be held to be insufficient. This line of
reasoning led to the industrial property offices in an increasing number of countries either
requiring or recommending that the written disclosure of an invention involving the use of a
new microorganism be supplemented by the deposit of the microorganism in a recognized
culture collection. The culture collection would then make the microorganism available to the
public at the appropriate point in the patenting procedure.