The purpose of this experiment is to obtain isolation of individual species of particles from the mixed culture. This is completed through the isolation technique of streak plate. The objective of this experiment is to replicate the technique of streak plate but on a much larger scale. Because it is on a larger scale the particles are able to be visually observed as they are isolated using the streaking technique as the experiment is conducted. The benefits of the streaking technique is when a cultures has multiple species they are able to be more easily identified once they have been isolated. This experiment is much like the experiments completed on an agar plate but on one a much larger scale and where techniques can be perfected before the use of agar plates and specimens are used. Because this experiment uses materials that represent those used in the streaking on agar plates the ability to simulate the events that occur when streaking is similar and allows for visualization instantly.
In this experiment materials will be gathered that are representative of the tools need to complete the actual experiment of agar plate streaking. The techniques used will be the same however the items that are used will be on a much larger scale. In replacement of flaming a loop the use of particle remover or water will be used to clean the utensils The end result of the experiment will show the isolation of the particles and degrees in consistency
Materials & Methods-
The materials used in the lab were collected as seen in Picture 1. For this lab multicolored sprinkles were used to represent small particles. Because of the variation in color these particles used created a mixed culture and therefore are it was not a pure culture. Ketchup was used for a medium and was mixed with the with the sprinkles to create a culture and was contained in a square tupperware to represent a culture tube. A spoon was used a a streak utensil and was cleansed using a cup of water as a particle remover. The spoon was cleansed between streaking using the particle remover. A disposable paper plate was used as the spreading surface.
In preparation for this lab the above materials were collected and the particles where mixed into medium, as seen in picture 2. The clean spoon which which represents the sterile loop for this lab was used to collect a sample of the mixed culture. The clean spoon or streaking utensil was held like a pencil while the tupperware dish (which represents the culture tube) was held at an angle as if to prevent from contaminating the culture from airborne microbes. The streaking utensil was held still as the tupperware dish was moved and the streaking utensil tip was dipped into and out of the mixed culture. Then the culture that was obtained on the streaking utensil was then streaked onto the paper plate or spreading surface using a back and forth motion, as seen in picture 3. Resulting in a larger area of more concentrated particles. The streaking utensil was then cleaned using the cup of water which represents the particle remover, as seen in picture 4. The streaking surface was then rotated 90 degrees. Using a cleaned streaking utensil the second streak was made from the middle of the of the first streak in a back and forth motion, as seen in picture picture 5. This streak significantly decreased the constancy of the particles from streak one. The streaking utensil was then cleaned the particle remover, as seen in picture 4. The streaking surface was then rotated 90 degrees. Using a cleaned streaking utensil the third streak was made from the middle of the of the second streak in a back and forth motion, as seen in picture picture 6. The third streak further decreased the consistency even further spreading out the individual particles. The streaking utensil was then cleaned using the particle remover, as seen in picture 4. The streaking surface was then rotated 90 degrees. Using a...
1. Leboffe, Michael J. and Pierce, Burton E.(2012). Breif Microbiology Laboratory Theory and application Second Edition, Common Aseptic Transfers and Inoculation Methods (pp. 26-38). Englewood, CO: Morton Publishing.
2. Leboffe, Michael J. and Pierce, Burton E.(2012). Breif Microbiology Laboratory Theory and application Second Edition, Streak Plate Methods of Isolation (pp. 39-44). Englewood, CO: Morton Publishing.
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