An improved apparatus and method for dispersion of a labeling conjugate in a diagnostic assay, the result being a one-step assay. An exemplary embodiment of the apparatus may include a voice response unit, a storage medium, and a voice print comparator The voice response unit may be configured to obtain a test voice print during a transaction between the consumer and the merchant. The host is provided with one or more links for inclusion within a page on the host website that correlates with a selected commerce object, which may be contextually related to material in the page.