Mixed Cellulose Ester Membranes-Plain ME 24, Gridded
                                                
                                                    Whatman gridded filters have clearly defined grid lines spaced at 3.1 or 5 mm intervals.
                                                    The special ink used is nontoxic and completely
                                                    free from bacterial growth inhibitors.
                                                    Whatman black mixed cellulose esters are available plain for automatic colony
                                                    counting applications, as well as gridded to assist in manual counting procedures.
                                                    Black membranes provide contrast between residue or cell colors and the filter
                                                    without having to counter-stain the membrane.