These operational procedures are for NCM-ELISA, an immuno-enzymatic test that uses nitrocellulose membranes instead of the polystyrene microtitration plates as a support for the reagents used in the serological reaction. The test is as sensitive as the direct double antibody sandwich ELISA (DAS-ELISA), easier to perform, and can be completed in a shorter period of time. It also has another very important advantage: the samples can be dotted onto the nitrocellulose membrane and stored for several weeks before continuing with the test; or they can be sent to another laboratory for development.