Discussion - Aseptic Technique

This discussion outlines the findings of the experiment and offers explanations/ reflections as to why the experiment was not as successful as hypothesised. Human error, especially attention to detail was the most significant reason for the results given.

There were many aspects of this experiment that did not succeed. For example, the scribing was not as successful as it was hoped to be. The lines were rounded off at the end and were uneven and dissimilar. Another aspect was the scribe itself. The scribe was not allowed to cool before scribing the e-coli, and when the scribing was taking place, a sizzling sound was heard as the scribe was dipped in e-coli. This could have potentially affected the experiment as it may have destroyed the e-coli. (57 degrees of higher kills bacteria) To avoid this, the scribe could have been cooled for at least 10 seconds.

Another reason as to why the experiment was not as successful as it should have been was because the results were from less than 24 hours before hand. This meant that the e-coli was not fully grown and the results were therefore unreliable and not the results that had been predicted. The table of results show that as the percentage of nutrient agar is increased, the e-coli growth is faster and grows in more quantity. However, no growth is shown in the 0%, 0.5% and 1% nutrient agar plates. The 0% was expected, however the plates that had some nutrient content within them should have had a small amount of growth. There are many factors contributing to these results including the factor mentioned before; the e-coli may have been killed with the scribe as it was too hot. Another factor was that clearly, the e-coli hadn't had enough time to grow and was not ready to be analysed.

Although there were many mistakes throughout the experiment, it was a success. The experiment gave the results that were hypothesised and supported the hypothesis thoroughly. However, if the experiment was done again, there are ways that could assist the experiment.

Three improvements to the experiment could be:

- To ensure that there is a sufficient amount of time so that the e-coli will be able to mature properly.

- If unable to secure additional time for the e-coli to grow, experiment with the temperature to accelerate the growth of the e-coli. This may not work, however it would be a useful and interesting experiment.

- If there is limited time, secure a different strain of e-coli that reproduces at a faster rate.

Also, a different way to do the experiment would be to change the nutrients to a variety of things. For example, something salty like vegemite and something sugary like jelly. These tests would support the idea that e-coli can grow at a different rate depending on what it is being fed.

Conclusion

The experiment