In the case that a culture is exposed immediately evacuate the class room and contact a lab technician immediately. Method When the experiment was carried out the first thing that needed to be attended to was having all the correct equipment and materials at hand. The following equipment and materials were gathered: A metal wire- a metal wire which has a high melting point created out a metal such as iron and is made into a wire with diameter of a about 2mm but yet is malleable and yet maintains high strength. Bunsen burner- A laboratory gas burner invented in 1855 by Roberts Bunsen.
The Bunsen burner has a vertical metal tube flows through. The vertical tube has a while located at the bottom of it which is used to admit air. When the whole is closed a yellow safety flame is displayed. Where as when the whole is open it displays a power dull blue flame with a faint blue outer flame with a vibrant blue core used u for combustion and heating. A bottle of pure yeast- A tube shape bottle with a screw cap containing pure yeast. Agar plate-A plate of agar that contains the correct nutrients for the yeast to grow. Petra dish- Circular dish with a lid which is transparent.
Once the equipment and the materials were gathered they were placed safely in the centre of the table. Firstly the Bunsen burner was connected to the gas tap. The next step took was lighting the Bunsen burner which was done by turning the gas tap 45 degrees to the right. Then a lit splint was took and placed over the pipe of the Bunsen burner at arms length at the Bunsen burn ignited. Prior to lighting of the Bunsen burner the air whole at the bottoms was closed which meant when I lit the Bunsen burner the yellow safety flame would appear.
Once the Bunsen burner had been lit I took hold of the metal wire and created a loop on the end of the wire. The wire was then took and placed in to the centre of the combustion flame of the Bunsen burner. The combustion flame was received by opening the air whole. Once the wire was in the centre of the combustion flame it was held there until it was glowing red this is formally known as ‘flaming the loop’. Whilst the ‘flamed’ wire was held in one hand the yeast bottle was took and the cap was unscrewed.
The neck of the bottle was then placed into the centre of the combustion flame and neck of the bottle was ‘flamed’. As the loop was very hot I was held to cool for a few second before being inserted in to yeast bottle to pick up a film of yeast culture. Once a film of yeast culture had been picked up the neck of the bottle was flamed again. With yeast culture film in the loop the Petra dish containing an agar plate was opened at 45 degree angle. With the Petra dish open the film was streaked along the agar plate in a zigzag fashion.
After the film had been placed on to agar plate the loop was then ‘flamed’ again. Any remaining yeast cells were killed of during the process of ‘flaming’. The Petra dish was closed and sealed with cello tape. A label was placed on the side of the dish the labelled stated the type of organism and the name of conductor of the experiment. Finally the Petra dish was checked, secured and incubated at 30i?? Celsius. Results As every good scientist knows the results are the main aim of the experiment and recording the results is even more important.
I managed to grow a successful yeast culture. View picture attached. Evaluation I will now evaluate my work to date be referring the aim set at the beginning of the assignment and will evaluate and analyse my performance and accomplishment the objectives. .Aim: During the course of this project I aim to successfully grow a yeast culture and sterilise the equipment that I use. I also hope to gain the skill of aseptic technique and hope to use it in high level science. Shown above is the initial aim which was stated within the introduction.
When I first created this aim I thought I would have an easy journey. As I carried out my experiment, the errors that I encountered were many, to my surprise. However, in the end I successfully carried out the experiment coming out with accurate results. Whilst carrying out this experiment I encountered many unexpected errors and I had to overcome them on the spot. The first error I encountered was the connecting of the Bunsen burner to the gas tap. This was a problem because I could not get the pipe from the Bunsen burner to the gas tap they pipe wouldn’t hold on the gas tap.
This problem could not be fixed so I decided the only way around was to switch the Bunsen burner. As I continued setting up the experiment I was required to form a loop on the end of my wire. As I formed the loop the wire snapped. Without the loop on the wire it was almost impossible for me to continue with my experiment so I decided to overcome the problem by replacing the wire and creating a looser loop. As I had now set up my experiment I began to conduct and as I got in to the second step of the process encountered another error.
The error the occurred was that when I ‘flamed’ the necks of the bottle I accidentally left it in the flame to long which cracked the entire bottle. The technician was informed and attended to the issue. Within the final stage of my process I was faced witch yet anther challenge. This time I had doped the open agar plate and contaminated it. The plate due to the fat that when I was opening it I was still holding the ‘flamed’ in my other hand and some how the wire touched the hand I was opening the agar plate with and I instantly reacted dropping the plate.
The mess was cleared up and I had to use another agar plate as this one was contaminated. From here on I encountered no obstacles or problems due to the fact I thought about potential problems and how to overcome them. As I have stated above how I had thought about potential problems and how I overcame them. My first and only potential problem was the ripping of the agar plate. This could have happened if when streaking the agar plate with the film of yeast I could have ripped the plate.
I decided that the only solution was to streak it several time with extreme care. Overall by looking at the problems and potential problems I had I think I didn’t carry out a very accurate experiment. With all the minor problems I think the accuracy was not as good as it could have been. I think that the method and the equipment and the materials for this experiment are great for maximum accuracy but they do not eliminate the chance for human error. The only problem with the method of this experiment is that it should be changed for two people instead of one.
This is because the method clearly needs another person for example holding a wire I one hand and then unscrewing and flaming a bottle with the other hand is clearly endangering people that is why I personally think this experiment should be conducted between to people. Over all out of the whole experiment I enjoyed the theory the most due to the fact that it enhanced me knowledge about preparing accurate chemical solutions and it showed me it just wasn’t a basic skill but a crucial skill which involved a high level of accuracy I also enjoyed conducting the experiment even though I encountered many errors I enjoyed finding a solution to them.
I also think that this experiment has challenged me mentally in every academic way. It has also helped me to develop personal thinking strategies. During this experiment I learnt quote a lot and enhanced my general knowledge of chemicals as a whole and I learnt practical skills of preparing chemical solutions which I will be able to use in the future. Over all this experiment has been an interesting and an enlightening experience which I have gained many skills and much knowledge even though I had encountered many problems I enjoyed the experiment thoroughly and would gladly repeat it.