The Spearman Estimator for Serial Dilution Assays

Abstract

To estimate the density of a specific organism in a suspension, a common method is to form a series of dilutions of the original suspension. Then from each dilution a specified volume, hereafter referred to as a dose, is placed in each of several tubes. Later the tubes are examined for evidence of growth of the organism. Suppose k + 1 dilutions are used with concentrations of zi = a-'zoI i = 0, + 1, +2, * , + k. z0 is the highest concentration of original suspension used and a > 1 is the dilution factor. The following notation will be used: