The Bühlmann Direct Saliva Melatonin ELISA (EK-DSM) is intended for highly sensitive, quantitative determination of melatonin in human saliva. This method calculates the binding (B) of each pair of sample wells as a percentage of the Zero samples, with the Blank-corrected absorbance of the Incubation Buffer taken as 100%. The percentage bound (vertical axis) versus the concentration of melatonin in pg/ml (horizontal axis) is plotted on lin/log axes. The best fit four parameter logistic curve through the standards is found and used to calculate melatonin concentration in salivary samples (pg/ml). Optional dilution values are applied to final concentration values.