Mechanical Preparation of Pour Plates for Viable Bacterial Counts of Milk Samples
Open Access
- 1 August 1973
- journal article
- Published by American Dairy Science Association in Journal of Dairy Science
- Vol. 56 (8), 1011-1016
- https://doi.org/10.3168/jds.s0022-0302(73)85298-1
Abstract
A machine for making bacterial pour plates to determine the viable bacteria counts of milk samples has been developed. Samples are automatically placed on a turntable conveyor which advances the sample under an arm that dips a .01-ml capacity cylinder and a .001-ml capacity loop into the sample three times. Then, a divided petri dish is positioned under the dipping arm, the milk in the cylinder and loop is flushed with 3 ml of dilution water, agar is pumped into the dish, and the sample and dish are each atutomatically removed from the turntable. The agar is solidified by passing the dish over a cold plate. The machine plates five samples of milk per minute.Twenty-six milk samples were compared by the standard plate count and machine plate cylinder techniques; 26 additional samples were tested by the standard plate count and machine plate loop methods. Criteria to compare the machine and standard plate methods included experimental error equal to or less than .005 in log10 units, average difference between geometric means less than 9% and interaction factor not to exceed .007 in log10 units. All criteria were satisfied by the mechanical cylinder and loop methods.Keywords
This publication has 11 references indexed in Scilit:
- Statistics in ResearchTechnometrics, 1977
- The Automatic Spreading of Bacterial Culture over a Solid Agar PlateJournal of Applied Bacteriology, 1971
- Cylinder Count Method for Determining Plate Count of Pasteurized Milk ProductsJournal of Dairy Science, 1970
- THE USE OF THE 0.01 ML LOOP IN THE PLATE LOOP METHOD FOR MAKING VIABLE COUNTS OF MILK1Journal of Milk and Food Technology, 1967
- COMPARISON OF PLATE LOOP AND AGAR PLATE METHODS FOR BACTERIOLOGICAL EXAMINATION OF MANUFACTURING GRADE RAW MILK1,2Journal of Milk and Food Technology, 1967
- REPRODUCIBLE VOLUME DELIVERED BY AN 0.01 ML “LOOP”Journal of Milk and Food Technology, 1966
- AN EVALUATION OF SIMPLIFIED METHODS FOR DETERMINING VIABLE COUNTS OF RAW MILKJournal of Milk and Food Technology, 1960
- A PLATE LOOP METHOD FOR DETERMINING VIABLE COUNTS OF RAW MILK1Journal of Milk and Food Technology, 1960
- A VOLUMETRIC PLATINUM ‘LOOP’Journal of Applied Bacteriology, 1954
- A Simplified Procedure for the Laboratory Examination of Raw Milk SuppliesJournal of Milk and Food Technology, 1941