Title: Bacteria Lab
Purpose:The purpose of this lab is to experiment the bacteria growth on some nutrient agar specimen. The bacterias we got are from objects of everyday use. Also to explore the growth of bacteria and the effect of the following treatments: disinfectant, soap.
Hypothesis for 4 unknown samples on specimen :If we take bacteria of an object with a piece of tape and put it onto the specimen, then the bacteria will grow, forming a huge population because of the space available and there is food for the bacteria to reproduce.
Hypothesis for aseptic technique:If we put bacteria onto the specimen and spread it around in a specific pattern using the loop, then the part where we started swiping the bacteria off of first will have the biggest colony of bacteria.
Procedure:
(Agar Plate A - Aseptic)
Turn on the bunsen burner
Take the loop and put it over the fire
Wait until the loop turns red and then take it off of the fire
Wait for the loop to cool down
Take the bacteria specimen your professor will provide to put onto the agar
Open the lid, put the lid over the fire until it gets hot enough till the bacteria is killed
Put the loop inside the test tube and collect some of the bacteria onto the loop
Briefly open the petri dish cover
Carefully swipe the loop onto the agar with a specific pattern
Tape the side of the petri dish so no bacteria can get into the nutrient agar
(Agar Plate B - 4 Random Samples)
Divide agar plate in the 4 quadrants (A, B, C, D) with a sharpie pen
Collect 4 (3) unknown samples' bacteria using the scotch tape
On quadrant A, take a clean piece of tape and carefully dab it onto the agar. (hopefully to see no bacteria growth on quadrant A)
On quadrant B, find a random object and stick tape onto it, then briefly put the tape onto the agar
Repeat the step from quadrant B for quadrant C and D but every quadrant should have a different sample
Tape the side of the petri dish so no bacteria can get into the nutrient agar
(Agar Plate C - Paper Disk)
Divide agar plate in the 4 quadrants (E, F, G, H) with a sharpie pen
Collect 3 paper disks from hole puncher and 1 sterile paper disk
Sterilize tweezers with heat/fire; let cool
With tweezers, place 1 paper disk (soaked in Soap) to quadrant (E) of agar plate
With tweezers, place 1 paper disk (soaked in Lysol) to quadrant (F) of agar plate
With tweezers, place 1 paper disk (sterile) to quadrant (G) of agar plate
With tweezers, place 1 paper disk (control) to quadrant (H) of agar plate
Tape the side of the petri dish so no bacteria can get into the nutrient agar
Materials:
-3 plates of nutrient agar
-1 paper disc soaked in Lysol
-1 paper disc soaked in soap
-1 control paper disc
-1 sterile paper disc
-scotch tape
Conclusion: In conclusion, my hypothesis was supported by the results. The results showed that the aseptic technique had bigger bacteria colonies from the start of the spreading of the bacteria and the end had smaller colonies. I think we can improve this experiment in the future if we can sample from anything in the school, although it will be dangerous. This experiment was pretty useful to my knowledge, as I did not know that bacteria can get into the specimen even opening the petri dish a little.
