There are four specimens obtained from the area of sample – one for each of the used male and female cubicles, and another one for each of the same cubicles after they were cleansed as routinely done by the janitor. The isolation of the microbes in the samples obtained from the lavatories needed to be inoculated to obtain a pure culture. Proper aseptic was applied throughout the inoculating process. [1] After preparing the culture media and applying the necessary aseptic techniques, the swab containing the inoculum was introduced to the media, and using a nichrome inoculating loop, the inoculum was streaked using the clock method. The clock method was performed by drawing four different quadrants or sectors on the back-side of the plate containing the culture medium. The four quadrants were drawn in such a way that at the last two lines of every sector there is small portion termed as a tail [2] that is the actual starting point of the next sector. Streaking is performed from the first quadrant, and after that the last line of the first sector is used to initiate streaking for the next sector and so on. This helps in reducing the microbial population entering the next sector, and thus the population of microbes gets decreased by several folds. [3] This is a great factor since the virulence of the microbes is also dependent on its number of colonies. Upon incubation, we observe that with each and every successive sector, the isolation and separation of microorganisms gets better. The clock method is suitable when there is a high population density in any sample or given culture suspension of microorganisms. [2]
References:
[1] Cardona, C.C., Tiburcio, J. (2012). Bacteriology Laboratory Manual. Espana, Manila: UST Publishing House
[2] Tortora, G. J., Funke, B. R., Case, C. L. (2010). Microbiology: An Introduction with Mastering Microbiology, 10th Ed.
[3]
References: [1] Cardona, C.C., Tiburcio, J. (2012). Bacteriology Laboratory Manual. Espana, Manila: UST Publishing House [2] Tortora, G. J., Funke, B. R., Case, C. L. (2010). Microbiology: An Introduction with Mastering Microbiology, 10th Ed. [3] http://www.squidoo.com/methods-for-the-isolation-of-bacteria