Sterile Water Dilution Lab

At the end of the 75 minutes, two 1.0 mL samples of the albumin/glucose solution from the beaker were added to two test tubes labeled solution end. Then, the dialysis tube was removed from the beaker and rinsed off with distilled water. Once the tubing was rinsed and blotted dry the final water weight was recorded. After measuring the final water weight, the contents in the tubing was dumped into a beaker and 1.0 mL of starch/sodium sulfate solution was added to two test tubes labeled bag end (Keith et al., 2010).

Introduction: Alka-seltzer contains three active ingredients, aspirin, sodium hydrogen carbonate and citric acid. It is used for headaches, migraines, and cold and flu symptoms. Alka-Seltzer is usually taken when dissolved in a glass of water. When placed in water a series of chemical reactions result into Sodium citrate and Sodium acetylsalicylate. The sodium citrate would act as the antacid for stomach pains, and the sodium acetylsalicylate would act as the pain reliever.

• Serially dilute the 4 mg/ml solution with buffer A to make working solutions of 400 µg/ml and 40 µg/ml.

If we were to repeat this lab, we would make sure to ensure the equipment was clean and the substances were not contaminated before proceeding. For chromatography, we would only put one drop from the micro pipettes onto the TLC plate, instead of the 6 we started out with initially. This would allow the substances to stay separate, and our results would be more accurate. We may also have touched the TLC plate during the experiment, so we would be more careful to only touch the edges of the plate.

There were several steps completed to prepare for the experiment. Three dialysis tubes were filled with approximately the same volume of distilled water and then were tied shut. The initial mass (in grams) of the tubes was taken using a triple beam scale. I then filled three 500 mL beakers with 400 mL of water each and dissolved different masses of solute (table sugar) in each beaker in order to make 5%, 10%, and 20% solutions. The beakers were labeled accordingly, and then 20 g, 40 g, and 80 g (respectively) of table sugar was weighed out using a digital scale and placed into the corresponding beakers. The sugar was stirred in using a stirring rod until all of the solute was completely dissolved.

The control in the experiment is distilled water, as it does not contain sucrose solution.

In order to minimize errors and to "place" the solutions in the same environment, the same volume should be extracted from each solution using the syringes.

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

The pipette was used to transfer 8 mL of the 0.5 molarity solution into the graduated cylinder. Distilled water was added to raise the bottom of the meniscus to the 20.0 mL line and the solution was transferred into the beaker after it was rinsed with the solution. The pipette was used to take a small quantity of the solution and rinse and then fill a test tube with the solution. The amount of 0.2 molarity solution needed to create 20.0 mL of 0.1 molarity solution was calculated as 10.0 mL. The pipette was used to transfer 10.0 mL of 0.2 molarity solution into the graduated cylinder and distilled water added until the bottom of the meniscus reached the 20.0 mL line. The solution was transferred to the rinsed beaker and then a portion placed into a test tube that had been rinsed with the solution. The amount of 0.1 molarity solution required to create 20.0 mL of 0.05 molarity solution was calculated to be 10.0 mL. The pipette was used to transfer 10.0 mL of 0.2 molarity solution into the graduated cylinder and distilled water added until the bottom of the meniscus reached the 20.0 mL line. The solution was then placed into a beaker that had been rinsed with the solution and then into a rinsed test

In the three lab visits to different steam, rivers, and watersheds the method in which we conducted to record our answers have been consistent. The way we conducted the studies have been done the same way for each visit. At each site we used a small table to hold items that will be used, kick seine nets, vernier kit, temperature sensor, pH sensor, conductivity probe, and dissolved oxygen probe. Also needed are data sheets for each different watershed to record the temperature, dissolved oxygen, conductivity, and the pH. You will also need water waders to be able to go into the water. As well as two small contains that you will fill up with water at each site, help when catch insects from the water with the kick seine net. Ice cube trays that

The purpose of this lab was for the student to get involved with his or hers new lab kit as well as being able to know, identify and use each other tools provided in the kit. Another key learning aspect of this lab is to teach the student how to measure properly the many units in the SI system. I will be using laboratory dilutions, measurements, and weights to then calculate using algebraic formula.

It was concluded that out of the 44 wells pipetted, 13 were magenta meaning they were positive for Coliforms. After placing both the 50ml tube and well plate under the ultra violet light, it was found that only one well plate was positive for Escherichia coli despite the fact that the 50ml sample mixed with the COLISURE packet was negative for Escherichia coli. The calculation for the total volume dispensed in the wells was calculated and was 0.2ml x 44 wells = 8.8ml. Then, the information gathered about the number of wells positive and negative for Escherichia coli was then plugged into the equation that will result in the number of cells per 8.8ml for both wells positive for Coliform and for wells positive with Escherichia coli. Using the calculation (1/V) x ln(total # of wells/# of negative wells) it was concluded that there were 1.75 cells per 8.8ml in the positive Coliform wells and 15.4 cells per 8.8ml in the one well positive for Escherichia coli. To find these answers the following equation was used for both Coliforms and Escherichia coli: (1/.2) x ln(44/31)= 1.75 Coliform cells per 8.8ml of sample, and (1/.2) x ln(44/43)= 15.4 cells of Escherichia coli per 8.8ml of

The purpose of this lab is to see the effects of pasteurization while emphasizing the process for serial dilutions.

Each test tube containing 9-ml of a dilution blank (distilled water) was aseptically inoculated with 1ml of Salmonella typhimurium phage. One test tube was a control that contained no phage and was diluted into a tube and poured on the plate. The first inoculation was the original phage suspension and from there we diluted it three more times in 9-ml dilution blank test tubes. Once the test tubes were inoculated .5-ml of each dilution was placed in soft agar tubes quickly, so that it would not solidify, and then were poured on the trypticase-soy agar plates. The TS agar plates were left to incubate for 6-10 hours. Once done incubating each plate was then counted to see how many plaques had formed on the bacteria lawn.

Purpose: To explore the effectiveness of different levels of concentration of antiseptic and antibacterial products’ prevention of bacterial growth.