Hydrophobic Grid Membrane Filter

- up to 1g food homogenate filtered through membrane filter (0.45 um pore) with 1600 wax grids - filter placed on agar medium surface - incubation (24-48h); counting of positive grids - calculate most probable number MPN = 1600 * 2.303 *log10(1600/(1600-c)) c = number of positive grid cells