Small World Project A Fresh Sample Soil

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To begin the Small World Project a fresh sample soil needed to be collected in order to perform the method of serial dilution, which was the first step of the project. The serial dilution used 4 agar plates and 5 dilution tubes. 5 grams of the soil sample was diluted it with 9.9 mL for the original broth. Then add 9.9 mL of sterile water to the 3rd, 4th, & 5th tube. Next is to vortex the original tube and place .1 mL into the 1st tube dilution, then take .001 mL of the 1st dilution tube and put it into the 2nd dilution tube; put .1 mL onto plate A. Next put .1 mL of the 2nd dilution tube and put it into tube 3. Vortex the tube & take .1ml of 3rd dilution tube and put it onto plate B. Thirdly, add .1 mL of the 3rd dilution to the 4th dilution tube, then vortex the tube. Put .1mL of the 4th solution onto plate C. Lastly, add .1 mL of the 4th dilution then add it to the 5th dilution tube, vortex it. Put .1 mL of the 5th dilution tube onto plate D. After the serial dilution the four plates were parafilmed and incubated for 24 hours to determine the number of colonies (Leboffe & Pierce, 2015). The second step of the project was to patch bacteria colonies from the serial dilution plates onto an agar. After getting the colony results from the dilution plates, next was to number 25 colonies using all the dilution plates. Sterile toothpicks were used to patch the colonies and a grid was used so that the colonies were numbered on each plate. The 25 colonies were patched on the plates and wrapped with parafilm to incubate for 24 hours. The third step was to take the colonies from the original patched plate and patch them onto two agar plates; one was labeled gram + and gram -. A number of 25 colonies were patched onto the gram + plate & t... ... middle of paper ... ... Gelatin Hydrolysis test which is used to determine if the exoenzyme gelatinase is produced. A sterile stabbing utensil was used to take a sample of the bacteria and stab the gelatin in a straight line down. The gelatin was incubated for 4-7 days (Leboffe & Pierce, 2015). The last step of the Small World Project is determine which antibiotics the bacteria is susceptible to. A sample of the bacteria was taken from the patched Gram + plate with the sterile loop and diluted with sterile water and placed on the agar plate. Next was to use a sterile swab to spread the dilution all over the plate. Lastly, the four antibiotic tablets Penicillin, Ampicillin, Chloramphenicol, and Erythromycin were placed spaced apart on the agar with alcohol sterilized tweezers & pressed down lightly on the agar. The agar was parafilmed and incubated for 16-18 hours (Leboffe & Pierce, 2015).

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