Effectiveness+of+Disinfectants


 * Effectiveness of Neutralizing Agents**. Peter Coetzee and Sarah Thames. The general purpose of this lab was to test the effectiveness of various neutralizing agents on bacterial growth in petri dishes. Scientific principles and methods present in the lab include equilibrium unfolding, streaking, zones of inhibition and bacterial growth. E. Coli was introduced to the plates via streaking, which were then introduced to their respective neutralizing agent. Effectiveness was gauged on the measures of the zones of inhibition. Two different methods were used in the introduction of the neutralizing agents: paper circles impregnated with the agent, and pipetting. In general, anti-bacterial soap was found to the most effective, with the largest zones of inhibition consistently found in the plates in which it was present. Hand sanitizer was effective to a certain extent, though less so than anti-bacterial soap. Hand soap had very inconsistent data, making conclusions difficult. Overall, the data suggest that anti-bacterial soap is the most effective substance with which to kill or inhibit bacteria. Keywords: petri dish, neutralizing agent, streaking, zone of inhibition, equilibrium unfolding, bacteria

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Several petri dishes used in lab

Table 1: Measures of Zones of Inhibition in First Method Sanitizer performed relatively well, with fairly consistent zones of inhibition. Hand soap’s data varied widely, with no trends easily indentified. Anti-bacterial soap performed very well, averaging the biggest zones of inhibition. Both distilled water and control plates had no observable zones of inhibition. Table 2: Measures of Zones of Inhibition in Second Method Sanitizer performed very poorly, with no observable zones of inhibition. This has likely to do with human error, rather than with the sanitizer itself. Hand soap performed as predicted, with ittle to no zones of inhibition. Anti-bacterial soap performed well once again. Distilled water displayed no zones of inhibition.
 * || Plate 1 || Plate 2 || Plate 3 ||
 * Sanitizer || 1.44mm || 2.4mm || 2.3mm ||
 * Hand Soap || 3.4mm || No bacteria observed || .1mm ||
 * Anti-Bacterial Soap || 4.3mm || 3mm || 2.9mm ||
 * Distilled Water || No zone of inhibition || No zone of inhibition || No zone of inhibition ||
 * Control || No zone of inhibition || No zone of inhibition || No zone of inhibition ||
 * || Plate 1 || Plate 2 ||
 * Sanitizer || No zone of inhibition || No zone of inhibition ||
 * Hand Soap || .4mm || No zone of inhibition ||
 * Anti-Bacterial Soap || 2.7mm || 3.5mm ||
 * Distilled Water || No zone of inhibition || No zone of inhibition ||

Journal Citation (Peter). Yip, CW. (2010). //A basic microbiology course for high school students. []// Journal Citation (Sarah) How to grow bacteria in agar petri dishes. (2011). Bacteria Growing Experiments, 1(1), []