Proper quality control involves the release testing of the final product through updated and validated methods. The release specifications of the product must be selected on the basis of the parameters defined during the characterization studies and the appropriate release tests must be performed. In case a release test cannot be performed on the final product but only on previous stages of the manufacturing, exceptions can be made after proper justification. However, in these cases adequate quality control has to rise from the manufacturing process. Specifications about the stability of the product, the presence or not of genetically modified cells, structural components and whether it is a combination product must also be defined.