PHOSPHATE BUFFER WITH MAGNESIUM CHLORIDE (MgCl 2 )
|Cat. no. D690||Phosphate Buffer with MgCl 2 , Dilu-Lok II™ Vial, 90ml||50 vials/case|
|Cat. no. D699||Phosphate Buffer with MgCl 2 , Dilu-Lok II™ Vial, 99ml||50 vials/case|
|Cat. no. U193||Phosphate Buffer with MgCl 2 , 500ml Polycarbonate Bottle, 500ml||10 bottles/box|
|Cat. no. U217||Phosphate Buffer with MgCl 2 , 1L Polycarbonate Bottle, 1000ml||10 bottles/box|
|Cat. no. U265||Phosphate Buffer with MgCl 2 , 500ml Polypropylene Bottle, 500ml||10 bottles/box|
Hardy Diagnostics Phosphate Buffer with MgCl 2 is used to prepare dilutions of samples for examination of water, dairy products, foods and other materials.
This product is not intended to be used for the diagnosis of human disease.
Phosphate Buffer with MgCl 2 is recommended by the American Public Health Association (APHA), for the recovery of injured microorganisms from dairy and food samples. Dilu-Lok II™ Phosphate Buffer with MgCl 2 is prepared as specified in the Standard Methods for the Examination of Dairy Products and Standard Methods for the Examination of Water and Wastewater . Potassium phosphate is added the formula to maintain the pH and the addition of magnesium chloride aids in the recovery of organisms that may be metabolically injured.
Ingredients per liter of deionized water:*
Final pH 7.2 +/- 0.2 at 25ºC.
* Adjusted and/or supplemented as required to meet performance criteria.
STORAGE AND SHELF LIFE
Storage: Upon receipt store at 2-30ºC. away from direct light. Media should not be used if there are any signs of deterioration (shrinking, cracking, or discoloration), contamination, or if the expiration date has passed. Product is light and temperature sensitive; protect from light, excessive heat and freezing.
Consult listed references for information on specimen collection and specific standard methods. (1-4)
General Dilution Guidelines:
1:10 Serial Dilutions:
1. Using a sterile pipet, aliquot 10ml of test suspension to 90ml of the Dilu-Lok II™ diluent. Mix thoroughly. This yields a 1:10 dilution.
2. Use a second sterile pipet to aliquot 10ml of the 1:10 dilution prepared in step 1 into a second 90ml filled Dilu-Lok II™ diluent. Mix thoroughly. This yields a 1:100 dilution.
3. Continue aliquoting 10ml of subsequent dilutions into 90ml filled Dilu-Lok II™ diluents until the desired concentration of test sample is obtained. Each succeeding dilution increases by a factor of 10. A separate sterile pipet should be used with each dilution.
1:100 Serial Dilutions:
1a. Using a sterile pipet, aliquot 1ml of test suspension to 99ml of the Dilu-Lok II™ diluent. Mix thoroughly. This yields a 1:100 dilution.
2a. Use a second sterile pipet to aliquot 1ml of the 1:100 dilution prepared in step 1a into a second 99ml filled Dilu-Lok II™ diluent. Mix thoroughly. This yields a 1:10,000 dilution.
3a. Continue aliquoting 1ml of subsequent dilutions into 99ml filled Dilu-Lok II™ diluents until the desired concentration of test sample is obtained. Each succeeding dilution increases by a factor of 100. A separate sterile pipet should be used with each dilution.
INTERPRETATION OF RESULTS
See listed references for interpretation of growth. (2,5,6)
MATERIALS REQUIRED BUT NOT PROVIDED
Standard microbiological supplies and equipment such as loops, other culture media, swabs, applicator sticks, incinerators, and incubators, etc., as well as serological and biochemical reagents, are not provided.
Hardy Diagnostics tests Phosphate Buffer with MgCl 2 for sterility, pH, and fill volume.
It can be difficult to accurately measure the pH of high purity water products as these products have low hydrogen ion activity. When troubleshooting potential pH problems associated with diluents ensure that the electrode is rinsed thoroughly before immersion in the water sample, that the pH is measured immediately after placing the electrode deep in the sample, and that the reference electrode provides minimal junction potential (0.1KCl provides greater stability and compatibility). Hardy Diagnostics recommends that pH measurements of Dilu-Lok II™ Phosphate Buffer with MgCl 2 be taken with electrodes specifically designed for low ionic strength water dilutions. (1,8)
USER QUALITY CONTROL
Phosphate Buffer with MgCl 2 should appear clear and colorless, with no precipitate or debris.
1. American Public Health Association. Standard Methods for the Examination of Water and Wastewater, APHA, Washington, D.C.
2. U.S. Food and Drug Administration. Bacteriological Analytical Manual. Arlington, VA. http://www.fda.gov/Food/FoodScienceResearch/LaboratoryMethods/ucm2006949.htm
3. Association of Official Analytical Chemists. Official Methods of Analysis , AOAC, Washington, D.C.
4. American Public Health Association. Standard Methods for the Examination of Dairy Products, APHA, Washington, D.C.
5. APHA Technical Committee on Microbiological Methods for Foods. Compendium of Methods for the Microbiological Examination of Foods, APHA, Washington, D.C.