Lab Report

The mole is a convenient unit for analyzing chemical reactions. Avogadro’s number is equal to the mole. The mass of a mole of any compound or element is the mass in grams that corresponds to the molecular formula, also known as the atomic mass. In this experiment, you will observe the reaction of iron nails with a solution of copper (II) chloride and determine the number of moles involved in the reaction. You will determine the number of moles of copper produced in the reaction of iron and copper (II) chloride, determine the number of moles of iron used up in the reaction of iron and copper (II) chloride, determine the ratio of moles of iron to moles of copper, and determine the number of atoms and formula units involved in

There are many reasons for identifying an unknown bacterium. The reasons range from medical purposes, such as determining if the unknown could cause ailments in living things or knowing what microorganisms are needed to make antibiotics to other purposes such as knowing the exact microorganism has to be used to make certain foods. This experiment was done by applying methods in order to identify an unknown bacterium.

In this experiment, an unknown bacterium was given to each individual student. The main purpose of this lab was to identify the given unknown bacteria going through a series of biochemical tests as one of the gram negative bacteria among six different Gram negative bacteria Escherichia coli, Enterobacter aerogenes, Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aeruginosa and Salmonella typhimurium. At the very beginning, streaking method; T-streak technique was used to isolate the pure colonies. For the morphological identification of unknown bacteria, Gram Stain Method was done. Biochemical tests that were conducted for the experiment

In this project, C. Elegans are hermaphrodite worms that will be used since they are easy to maintain in lab, as well as have short life cycles. The gene that the project attempted to knockdown in C. Elegans with RNAi treatment is the unc-22 gene. RNAi disrupts gene expression in the presence of double stranded RNA (dsRNA) that is complementary to target gene sequence. The unc-22 gene codes for a muscle protein called twitchin in wild-type worms. The Unc-22 is required for muscle regulation and maintenance in C.Elegans. To verify that the RNAi treatment worked, would check the unc-22 mRNA levels in the worms, in addition to phenotype observation.

There were two tubes used in this process: the tube that contained the primary culture and the tube that contained the nutrient agar where the unknown bacteria would grow. First, the inoculating loop was flamed. After removing the caps of both the test tubes, they were flamed to prevent contamination of the unknown bacteria. The inoculating loop was cooled for a few seconds and was then placed into the test tube containing the bacteria. The inoculating loop with the bacteria was placed into the nutrient agar test tube for cultivation. Before the test tubes were capped, they were flamed once again. Also, isolation of the unknown bacteria had to completed. Nutrient agar was placed in the petri dish, and was left to gel for a few minutes. After the agar gelled, the inoculating loop was used to acquire bacteria and streak the unknown onto the plate for

The test tube was labeled with the bacteria identifying number. The cap on test tube was removed, and the lip of the test tube was flamed. Next, the Bunsen burner was used to sterilize the inoculating loop. Then, bacteria were picked up from the working plate with the loop and the agar was inoculated. The loop was then re-flamed. Finally, the plate was placed in the 37˚C incubator and left to sit for 48 hours and any changes in color were observed. A negative result appears green, and a positive result appears blue. This is because it tests for the organism’s ability to use citrate as its sole source of carbon, and if it does then it produces ammonia and ammonium hydroxide which make the medium basic, changing the green agar blue (Leboffe & Pierce,

In the method of continuous variations the total number of moles of reactants is kept constant for the series of measurements. Each measurement is made with a different mole ratio of reactants. A mole ratio is ratio between the amounts in moles of any two compounds involved in a chemical reaction. Mole ratios are used as conversion factors between products and reactants in many chemistry problems.

October 17, 18, and 19, samples were collected from multiple sites along the BSR. The class was split into groups, and samples were collected from seven separate locations along the river and WWTP. There was also a sample collected by the S which is located between sites four and five. For each of these sites, there were ten groups from other labs that also collected a sample from the BSR. At site two of the river, the location included multiple sources of possible contamination. A drainage site was located 200 yards upstream, along with a small PVC drainage pipe next to the collection site. Not only was there drainage running into the river, the site was under a bridge, and contained other trash scattered throughout the area. The

The techniques commonly used for isolation of discrete colonies initially require that the number of organisms in the inoculums be reduced. It is essentially a dilution technique that involves spreading a loopful of culture over the surface of an agar plate. The resulting diminution of the population size ensures that, following inoculation, individual cells will be sufficiently far apart on the surface of the agar medium to effect a separation of the different species present. Although many type of procedures are performed, the four ways or quadrant streak is mostly

All it takes is one single cell to start a pure bacterial colony. This lab allows researchers to observe isolated highly concentrated samples of bacteria, to view their traits and to isolate pure colony samples for use in future experiments. Unfortunately successful isolation was not achieved in this lab. Possible sources of error could be that the streaking was too close together resulting in an unsuccessful isolation, the loop was not flamed adequately which permitted carryover of bacteria from one sector to the next or forgetting to let the loop cool before touching the agar. To expand this lab, researchers could collect a single colony from an agar plate and grow it inside a nutrient tube to observe the oxygen nutrient requirements for that specific sample of

The second experiment will be conducted to determine which purification method is best suitable in eliminating the largest number of bacteria colonies as well as safe for drinking. These purification methods include, chlorination, boiling and filtration. The third experiment will be conducted to determine the effect of temperature on bacterial growth. Using Micrococcus Subtilus, 1ml will be grown and left to incubate at three temperatures. The incubation temperatures will be 0 Degrees Celsius, 20 Degrees Celsius and 37 Degrees

Still holding the vial at a 45 degree angle, the swab was inserted into the vial to soak up the S. marcescens for 10 seconds. Partly lifting the lid of one petri dish, shielding it over top like an umbrella, we inoculated S. marcescens onto the agar growth medium in the petri dish. We repeated these steps 2 more times to inoculate all 3 petri dishes. Once all three plates were inoculated with the S. marcescens we removed our forceps from the alcohol. We air dried them, and then passed them through the flam to sterilize them. Using the sterile forceps we placed the c disc in the center of a petri dish and press down lightly to ensure that it stayed. It is then labeled it C, for the control group, 5 for the replicate number, along with the date and time of the class. Again we sterilize the forceps and place the T disc into the next petri plate. It is labeled the same way but with a T for tetracycline. The T disc contained 30ug of the antibiotic. We repeat the sterilizing of the forceps one more time and place the Chl disc on the remaining petri plate and labeled it Chl for chloramphenicol. The Chl disc contained 30ug of the antibiotic. Once all 3 petri dishes are labeled they were placed upside down to prevent water droplets from falling onto the nutrient agar substrate. The last step to the experiment was to clean up. We placed our swabs in a waste beaker, cleaned up our work stations, and then washed our hands with soap and

The results indicate that the MIC of Colistin that is necessary to kill E. coli is actually 0.78 μg/mL. This MIC was concluded because there was no growth present 0.78 μg/mL while the 0.39 μg/mL plate and 1.56 μg/mL plates both showed growth of colonies respectively. The hypothesized MIC was 2.0 μg/mL, but our results point to a smaller MIC of 0.78 μg/mL. None of the other plates exhibited colony growth, but our results showed there was small specs of abnormally growing cells of some sort on plates the 50 μg/mL and 25 μg/mL, and also the 0.78 μg/mL which is this experiment’s MIC, exhibited these abnormal cells. The abnormal growth might be associated with possible contamination of the specimens on those individual agar plates that exhibited this growth since there was no contamination present in the control agar plates.

In order to obtain well-isolated discrete colonies, the quadrant streak and spread technique was used. This allowed dilution of the original microbial material over the entire surface of the plate. As the original sample was diluted by streaking and spreading it, over successive quadrants the number of organism decreases. Usually by the third or fourth quadrant only a few organism were transferred on the by the inoculating loop and theses produce a few isolated

A fresh pipette was used to transfer 0.5ml of broth culture of E. coli, to be inoculated, into a tube of molten agar previously boiled to drive off oxygen. The tube was then rolled to distribute the bacteria and allowed time for the agar to harden. The tube was incubated at 37oC for 48 hours. The procedure was repeated for broth cultures of the bacterium Clostridium sporogenes and B. Subtilis.