A bacterial culture contains a mixture of bacteria. The bacteria should be of two different clones: H0 and H1. To perform the assay, first dilution the bacteria with 10-3, then 10-2, and finally 10-3. To initiate the competition, add 500uL of each phage strain to a tube labeled "Phage Comp." and place it in a 37degC shaking incubator for 24 hours. When the bacteriophage cultures have reached the desired concentration, discard the HC blank, insert the empty 13mm pipette into the waste tube rack, and wait for 5 minutes for the mixture to solidify.
The amount of phages in the mixture depends on the type of cells and phage used in the assay. The number of phages in a microliter pipette tip is determined by dividing the amount of bacteria in the sample by the amount of bacteriophage in the sample. If the bacteriophage in the mixture is larger than the bacterial cells, a higher dilution is required to obtain accurate results.
A bacteriophage dilution is necessary to determine how many bacteriophage were present in the sample. To do this, you should use calculated volumes from the previous experiment and new saline wells. The dilution series must be repeated until the bacterial dilution reaches a multiplicity of ten.
The bacteriophage suspension in the microliter pipettte tip was mixed with 600 g of finished dairy compost. The final moisture content was 50%, and the mixture was then placed in a shaking incubator overnight. The samples were divided into four parts of 150 g each and sprayed with 3 ml of SM buffer containing 50 mM Tris-Cl, 0.1 M NaCl, and 8 mM MgSO 4 *7H 2 O. After mixing the samples, they were spotted onto soft-agar overlay plates.
The five bacteriophage mixture was diluted to a concentration of 10-6 CFU/mL in the microtiter tube. The five Salmonella strains were diluted to a concentration of 10-6 phage in the microtiter plate. The samples were visualized by taking an optical density every hour for 9 h. After nine h, a second bacterial culture was added. The final batch was prepared by repeating the experiment at the same multiplicity.
Using a microtiter tube, add 30uL of the P0 phage mixture to the prepared 600 g of finished dairy compost. Then, mix the samples thoroughly and leave them to stand at room temperature for at least 24 hours. Then, divide each sample into four equal parts, each containing three hundred grams. The resulting bacteriophage mixtures were diluted to a concentration of 10-7.
Using a bacteriophage pipette tip, we sprayed S. Typhimurium 8243 into 600 g of finished dairy compost with a final moisture content of 50%. The samples were mixed thoroughly and stored overnight at room temperature. On day three, the samples were divided into four 150 g portions, and three ml of SM buffer (50 mM Tris-Cl, 0.1 M NaCl, 8 mM MgSO4*7H2O) were added to each of the four samples. A total of one hundred and thirty-three bacteriophage were successfully sprayed into the four separate microtiter tube.
After mixing the phages, ph6 was sprayed on 600 g of finished dairy compost. The final moisture level was 50 %. The samples were then kept at room temperature for 24 hours. On day three, the samples were divided into four 150-g portions. Each sample was sprayed with three ml of SM buffer containing eight mM MgSO 4*7H2O. The bacteriophage mixtures were weighed and the MgSO4 concentrations were determined manually.
Several studies have shown that the agar layer method is a good method to determine the number of phages in the sample. The phages must be diluted in agar to 10-7 ml. After the dilution, the agar is pipetted into a soft agar tube. The bacteriophage must survive for five days in the agar.