An assay test kit is used in a mouth rinse sample collection procedure
involving collecting a mouth rinse sample from a patient. A neutrophil
reactant diagnostic reagent is delivered to the rinse sample immediately
after collection. Diagnostic reagents containing diammonium salts that
are reactive with neutrophil enzymes are added to the sample to produce
visually discernable colour change in the solution after a selected
period of time. Most preferably, the reagents are selected to produce a
colour change after a period of time. The reaction is then measured by
comparing the resulting sample colour change by eye or mechanically to a
standardized colour chart/swatch that correlates with predetermined
neutrophil concentrations and/or periodontal disease levels.