Alex

Alex Hung Lab Science 9 Biology Investigations Effectiveness of Anti Bacteria products

Examining the effectiveness of different anti-bacterial products on various bacteria’s


 * Relevance:**

Unicellular organisms, or sometimes known as bacteria’s, are all over earth’s surface and its atmosphere. Some bacteria’s benefit human beings, while others are harmful to humans. Sadly, most bacteria’s that co-exists with us human beings are proved to be harmful to us. Thus, many anti bacterial products were developed, in order to kill the harmful bacteria and prevent us from illness. However, we are not sure of the effectiveness of the anti bacterial products. The only way to find out is to put these products to a test. In order to find out the effectiveness of different anti bacterial products, our biology investigation is based on examining the effectiveness of different bacterial products on various bacteria’s. In our experiment, we used common bacterial cultures which co-exist with us, such as the bacterium’s who live on door knobs or the keyboard. On the other hand, we also used common anti bacterial products, such as rubbing alcohol, to test its effectiveness against various types of bacteria.


 * The Goal:**

Our goal for this biology investigation is to find the effectiveness of different types of anti bacterial products on various types of bacteria. We want to find how effective, in terms of how quick and how completely, does different anti bacterial products kill bacteria.


 * General Expectations and Models:**

We used many different types of anti bacterial products on bacteria. Generally, we expect that either anti bacterial products such as rubbing alcohol or Sodium Hydroxide (a.k.a. Antiseptic spray) would do the best job in terms of killing bacteria.


 * Materials:**

Below is a list of materials we used for our biology investigation:

- Agar dish - Bacterial samples taken from a door knob - Bacteria samples taken from a keyboard - Bacterial samples taken from the bottom of a shoe - Bacterial samples taken from the edge of a garbage can - Bacterial samples taken from our fingers - Mouth Wash - Rubbing Alcohol - Hand soap - Toothpaste - Water - Ethyl Alcohol - Sodium Hydroxide - Salt Water - Hand sanitizer - A Small Knife (for cutting out different bacterial samples from the agar) - Tweezers (for picking up bacterial samples from the agar) - The incubator (for quickening the growth of bacteria, provided by the science lab) - An agar dish of bacterial samples taken from the same places as the ones which are going to be tested. However, we would not do anything with this one, so that we could compare the one we did not do anything with to the one we experimented with.


 * Methods and Procedures:**


 * 1) First, we take an agar dish containing an already grown sample of bacteria taken from the keyboard. We placed a rubbing alcohol wipe directly on top of the bacteria inside the agar dish.
 * 2) We did the same procedure written in step 1, except we used other anti bacterial substances and applied it directly onto the bacteria in the agar dish. Here is a list of the anti bacterial substances we used for this experiment: (1) mouth wash, (2) Hand soup, (3) toothpaste, (4) water, (5) ethyl alcohol, (6) sodium hydroxide, (7) salt water, and (8) Hand sanitizer.
 * 3) We stored the agar dishes in room temperature in the science lab cupboard, so that the bacterial samples would not be affected by different variables such as sunlight, moisture, etc. We waited for a week for the anti bacterial product to start its effect on the bacterial samples.
 * 4) After a week, we took the bacterial samples back out from the cupboard and measure with a ruler how the diameter of certain bacterial colonies have changed. We also took sketches of the same sample of bacteria under the microscope before and after the investigation.
 * 5) Compare the results of the effectiveness of different types of anti bacterial products. Find the ones which have the best result in its ability on killing bacteria.