Introduction-
The purpose of this experiment is to obtain isolation of individual species of particles from the mixed culture. This is completed through the isolation technique of streak plate. The objective of this experiment is to replicate the technique of streak plate but on a much larger scale. Because it is on a larger scale the particles are able to be visually observed as they are isolated using the streaking technique as the experiment is conducted. The benefits of the streaking technique is when a cultures has multiple species they are able to be more easily identified once they have been isolated. This experiment is much like the experiments completed on an agar plate but on one a much larger scale and where techniques
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The particles were even more narrowed down in this final streak allowing for further separation of each individual particle. The streaking utensil was cleaned using the particle remover and returned to the utensil storage area. And the other items collected for this lab were cleaned and returned to their storage areas.
Results-
The particles that were collected for the lab were very concentrated prior to being mixed into the medium. Once the particles where mixed into the medium they was a decreased in their concentration as the medium allowed for separation by filling the spaces between them. Once the first streak was made it was slightly less concentrated and this allowed for the particles to be spread out over the surface. The concentration of particles that were spread with each streak continued to decrease. In the final streak, as seen in picture 7, the particles were separated almost to the point of being able to individually identify each color of particle. Much as the same results that you might see with a mixed culture that was completed in a lab and final results reviewed under a microscope.
Discussion-
The conclusion that was made from this experiment was that as the streaking is completed the consistency as well as the concentration degrees allowing for a more accurate identification of the individual particles. The results lead me to this conclusion because as the streaks were completed the
7. Tape the strip to a pencil and rest the pencil on top of the jar so that the strip hangs into the jar. The goal is to have the end of the chromatography strip just touching the surface of the solvent solution, with the colored dots above the surface of the liquid. Make sure that the colored spots do not come in direct contact with the liquid in the bottom of the glass.
1) Apply the stain to your first unknown slide and examine it under the microscope.
Read in your lab manual about the following agar mediums: Blood Agar (pg 168), EMB Agar (pg 170), Mannitol Salt Agar (MSA)(pg 172) ), MacConkey Agar (pg 174), and PEA Agar (pg 176) to answer the following:
Begin by labeling two sets of 7 different 1.5 ml tubes 0 thru 6. Obtain 1 more 1.5 ml tube and label it B for the blank. Obtain 1 sample of 15 μls from each of the serially di-luted tube concentrations and put it in its corresponding 1.5 ml tube. Now add 525 μl of media in each 1.5 ml tube, followed by 60μl of Alamar Blue in each tube. Close the lids of all the tubes and vortex for 5 seconds. In order to make the blank, add 180 μl of media and 20 μl of Alamar Blue in another 1.5ml tube.
Lab Day 2: The first procedure that was done was a simple stain to identify the bacterial shape. Bacteria tends to be transparent, so a stain must be use to color the cells of the bacteria so it can be viewed under a compound microscope. After heat-fixing three separate loopfuls of my unknown bacteria onto a slide, I used Methylene blue, Safranin, and Crystal violet to stain the three different samples. After rinsing the slide and observing my finding under the microscope, I
In this experiment, we wanted to investigate which surfaces in the school had the most bacteria, and we thought that the surfaces used more would have the most bacteria. For this experiment we used agar plates, cotton swabs and distilled water in order to see how much bacteria was on each surface. Cotton swabs were wet with distilled water and then the swabbed ws wied on a 2 inch space of the surface and twisted to cover the entire swab.once we swabbed the surface, we wiped the swab on the plate in a zigzag motion holding it upside down. The girls bathroom sink handle had 389 bacteria, and the boys bathroom by the football field had 0. We saw that places commonly used such as the bathroom sinks, door handles and railings contracted the most bacteria.
Materials and Methods: During this experiment 4 experiments were used to determine the identity
Upon obtaining the unknown organism, it was important to make a streak plate of the bacteria on TSA. The purpose of doing so ensures that we have pure cultures of the unknown to be used in further testing and not a mixed culture. The first test used was a gram stain. It is a differential stain that helps distinguish between gram-positive and gram-negative
You can grow microorganisms in liquid media or on solid media. Most bacteria can be grown in labs as long as the media contain a source of the major nutrients; carbon, nitrogen, sulphur, and phosphorous. They may also need to have other nutrients. These nutrients are made into a broth and the pH and salinity can be adjusted. The nutrient broth is placed in test tubes, which are plugged with cotton wool, capped with foil and then sterilised in an autoclave, at 121c for 20minutes. These tubes are then cooled before they are inoculated. To prepare the streak plates we dipped an inoculating loop into ethanol then placed it in the flame until the loop glowed red. Still holding the inoculating loop by its handle we removed the lid from
Table 1 shows the steps and color results after each reagent was added to bacterial smear slide. Before any reagent was added to the heat fixed bacterial slides unknown bacteria was colorless. The primary stains reagent, Crystal Violet was added to the slide the unknown bacteria color was purple. Then, Iodine mordant the color of cells still remained purple. After adding the decolorizer alcohol gram + would remain purple and the purple color from the gram- would be removed and it would become colorless. The last counterstain safranin was added to the slide a gram+ would remain purple and the gram – would turn pink or reddish in color. Meanwhile, after the gram staining, one were able to identify under the microscope that unknown bacteria
Error Analysis One scientific error was that the classroom lights were turned on while observing the spectral tubes with the spectroscope. The interference of observing the spectral tube with the classroom lights on in the opposite room may have disrupted the observed line spectra. For instance, some of the colored lines observed through the spectroscope, while directed towards the spectral tubes, could have taken into account of the classroom lights. As a result, the sequence of the colored lines observed from the spectral tubes could have included the colors emitted from the classroom lights. Therefore, the colored lines of the unknown element observed with the spectroscope may have not been cadmium due to the effect of the classroom lights
In the 10-3 pasteurized sample, the plate exhibited 71,000 cells/mL. The results of the additional dilution samples contained too few colony forming units to count. However, in the 10-7 dilution, although the plate demonstrated 12 colonies, there should have been no colony forming units on this plate. The reasons for this could have been that this sample was contaminated from “double-dipping” the sample before dispensing it onto the plate or when using the pipette, it mistakenly was inserted in a higher concentration sample and then immediately to a lower concentration sample before it was dispensed onto the plate.
The first part of the experiment dealt with breaking down the spinach leaves in a mortar and pestle. Acetone was added to this to help with the breakdown of the spinach leaves. Once the spinach leaves were broke down enough that you could see the particles
On each slide a drop of the culture and it was covered with the cover slip. It was made sure that a clean pipette, slide and cover slips were used when sampling that was to avoid contamination. Then the compound microscope was used to examine the live culture under the low magnification that was followed by observing with the medium power. Then each organism that was observed was record in the table that was done for all the slides. Then the percentage abundance for each organism was estimated and recorded for each week.
2. Introduction: Each student was given unknown bacteria and was instructed to perform a variety of experimental tests that would help to identify their bacteria. During the process of identification, the unknown bacteria was added to many different testing medias using aseptic technique. They are as follows: lactose fermentation on eosin methylene blue (EMB), TSI (Triple Sugar Iron agar), Phenol red sucrose, the SIM test, H2S by SIM, IMViC (indole, motility, voges-proskauer, and citrate), Urease (urea broth), PDase (Phenylalanine Deaminase), Lysine Decarboxylase, and Ornithine Decarboxylase. Colonial morphology on EMB was used to