The name to this lab is identification of unknown species. To know the species from unknown culture, our instructor handover test tube labeled with different number to all students each student with different number. I got test tube labeled #15 culture, which was assigned our instructor. We need to use different media and reagents to work safely and correctly. Before started to working we need to know how to do Gram Stain technique and biochemical testing to determine the name of the unknown species. We used 18 media with 15 reagents, to determine unknown species, which was provided by the Eastfield Dallas community College’s science department. All the methods to determine the “Unknown Lab” were in the book written by Tammy Oliver, Ph.D. …show more content…
After that bolt the slide dry with bibulous paper. After that examine the slide under the oil immersion lens. After determining the Gram stain reaction, 18 specific biochemical tests were performed for further analysis. The way of biochemical test was different but need to incubate at 37 degree Celsius. Phenol red lactose, phenol red dextrose, phenol red sucrose, methyl red, voges-proskauer, citrate utilization test, urea hydrolysis, and nitrate reduction are the media which are in test tube as liquid. Which were use Inoculating loop to deep tube with assigned bacteria. Triple sugar iron, and citrate utilization are in slant and we use Inoculating needle to deep tube with assigned bacteria. Again, starch hydrolysis, casein hydrolysis, lipid hydrolysis, oxidase test and catalase test were test from agar plate which use inoculating loop. For those media, which were in agar plate, inoculate with loop by making a line streak down the center of the agar. After that all 18 medias need to incubate at 37 degree Celsius for 48 hours. After 48 hours, some media show bacteria’s characteristics and morphology without adding extra reagent. Some media need reagent to examine morphology and physiology. Experiment such as MRVP needs methyl red, Barritt’s A, and Barritt’s
I identified the genus and species of an unknown bacterial culture, #16, and I applied the following knowledge of morphologic, cultural and metabolic characteristics of the unknown microorganism according to the laboratory manual as well as my class notes and power point print outs. I was given an incubated agar slant labeled #16 and a rack of different tests to either examine or perform myself; the tests are as follows: Gram Stain; Nutrient Gelatin Test; Carbohydrate Fermentation; Dextrose, Lactose and Sucrose; IMVIC tests; Citrate, Indole, Mythel-Red and Vogues Proskauer test; as well as a Urease and TSI Test. Materials and Methods/Results Upon receiving the Microorganism (M.O.) #16, I prepared a slide by cleaning and drying it. Then, using a bottle of water I placed a sterile drop of water on the slide and used an inoculating loop, flame sterilized, I took a small sample of the unknown growth in my agar slant and smeared it onto the slide in a dime sized circle and then heat fixed it for ten minutes.
Solid A was identified to be sodium chloride, solid B was identified to be sucrose, and Solid C was identified to be corn starch. Within the Information Chart – Mystery White Solid Lab there are results that distinguishes itself from the other 4 experimental results within each test. Such as: the high conductivity and high melting point of sodium chloride, and the iodine reaction of corn starch. Solid A is an ionic compound due to its high melting point and high electrical conductivity (7), within the Information Chart – Mystery White Solid Lab there is only one ionic compound which is sodium chloride, with the test results of Solid A, it can be concluded that is a sodium chloride. Solid B was identified as sucrose due to its low electrical
Each test that was used in the lab for the unknown bacteria had been performed on many different bacteria and shown that each test has different results depending on the bacteria given. The first test, the Gram stain, confirmed that the unknown bacterium was a gram negative bacilli. After performing the remainder of the tests and comparing them to the twelve negative bacteria that it could be out of it was basically a process of elimination. Basically looking at all the results and seeing which tests separated positive verses negative results the most. After reviewing all of the tests the first test that stuck out besides the gram stain was the lactose fermentation, followed by the citrate utilization test and then by the indole test. The lactose fermentation test eliminated seven of the 12 bacteria. From the five bacteria left the citrate utilization test eliminated who more of the bacteria, and last the indole test eliminated two of the three bacteria left leaving only one bacterium left. After comparing the results to the results of the 12 tests and separating which tests were positive and negative for each it was obvious that the bacteria had to be Shigella
The isolate possesses some enzymes required for hydrolytic reactions. Hydrolytic enzymes found to be secreted from the bacterium, are -amylase, casein, and PYRase. In the starch hydrolysis and casein tests, there was a zone of clearing around the bacterium, which was indicative of the secreted enzymes necessary to break down starch and casein. In the PYR test, the presence of PYRase was detected by a color change to red on the PYR disc after the addition of the PYR reagent (p-dimethylaminocinnamaldehyde). Hydrolytic enzymes for which the EI tested negative were urease, gelatinase, and DNAse. In the Urea Hydrolysis test, it was observed that the urea broth did not have a color change, indicating that there was no urease secreted to break down urea in the broth. Similarly, there was no gelatinase present to break down gelatin in the Gelatin Hydrolysis test, so the nutrient gelatin remained solid. It was concluded that the EI does not possess DNase because there was no clearing zone around the bacteria, indicating that DNA had not been
Forensic Science Introduction: Someone in a restaurant has suddenly fallen ill and a mystery powder has been discovered with the victim. As the chief investigator, your duty is to identify the mystery substance through a lab. In this lab, it will consist of five known compounds and one unknown compound. Your job is to distinguish which one out of the five substances is the mystery powder. To figure out the mystery matter you will have to compare their physical and chemical properties and match them with the appropriate compound.
After 5 days of growth each slant was tested using the gram staining technique to confirm the complete isolation of the bacteria. Both isolations were completely successful. Then each sample of bacteria was subjected to a series of tests for identification.
Streak plate technique was used to isolate pure culture for each bacteria (2). The Gram stain was used to determine Gram reaction and morphology of each bacteria (2) Selective and differential media such as, salt agar, MacConkey agar and blood agar were used for bacterial identification (2). Gelatin deeps were inoculated to detect production of gelatinase (2). Starch Agar plate were inoculated to detect amylase (2). Ocular reticle used to determine bacteria size (2). Motility deeps were inoculated to detect motility on bacteria (2). Thioglycollate broth used to determine oxygen requirements (2). Carbohydrate fermentation
The purpose of this study is to identify an unknown bacterium from a mixed culture, by conducting different biochemical tests. Bacteria are an integral part of our ecosystem. They can be found anywhere and identifying them becomes crucial to understanding their characteristics and their effects on other living things, especially humans. Biochemical testing helps us identify the microorganism present with great accuracy. The tests used in this experiment are rudimentary but are fundamental starting points for tests used in medical labs and helps students attain a better understanding of how tests are conducted in a real lab setting. The first step in this process is to use gram-staining technique to narrow down the unknown bacteria into one of the two big domains; gram-negative and gram-positive. Once the gram type is identified, biochemical tests are conducted to narrow down the specific bacterial species. These biochemical tests are process of elimination that relies on the bacteria’s ability to breakdown certain kinds of food sources, their respiratory abilities and other biochemical conditions found in nature.
3.) Divide your 30g of white substance into the 4 test tubes evenly. You should put 7.5g into each test tube along with the water.
These labels indicated the lactose solution that was be placed into the mini-microfuge tubes. The varying lactose ph solutions were obtained. The four miniature pipets were then used, (one per solution,) to add 1mL of the solution to the corresponding mini-microfuge tubes. When this step is completed there were two mini-microfuge tubes that matched the paper towel. Then, once all of the solutions contained their respective lactose solutions, 0.5mL of the lactase enzyme suspension was added to the first mini-microfuge tube labeled LPH4 on the paper towel, and 4 on the microfuge tube. As soon as the lactase enzyme suspension was added to the mini-microfuge tube, the timer was started in stopwatch mode (increasing.) When the timer reached 7 minutes and 30 seconds, the glucose test strip was dipped into the created solution in the mini-microfuge tube for 2 seconds (keep timer going, as the timer is also needed for the glucose strip. Once the two seconds had elapsed, the test strip was immediately removed, and the excess solution was wiped gently on the side of the mini-microfuge tube. The timer was continued for 30 addition seconds. Once the timer reached 7:32 (the extra two seconds accounting for the glucose dip), the test strip was then compared the glucose test strip color chart that is found on the side of the glucose test strip
My breaching experiment involved three social norms. These social norms forced people to be in an uncomfortable situation and make a decision as to how they should react to it. The first social norm I experimented with was sitting next to someone in an uncrowded movie theater. I chose this because of the awkwardness it caused. At all three of my trials, occurring from 1-9 pm, there were over fifty empty seats at Carmike on February 21st. The next social norm I analyzed was sitting in someone’s assigned seat. This was chosen because I felt it would be engrossing to observe the different reactions fellow high school students retaliated with, all being different races. At Liberty High School I took someone’s assigned seat five different times,
Forensic toxicology is one of the oldest disciplines in forensic science history and dates back hundreds of years. However, the actual understanding and examination of forensic toxicology only dates back for about 200 years. Due to the development of technology, this discipline has been able to progress and flourish.
A science kit is basically a toy or collection of toys for kids, but scientific! What do we mean by that? Well, as opposed to a doll or toy car, for example, a science kit is a science project or group of projects consisting of hands-on experiments that often result in a fun science toy. Science kits, such as the ones sold by Science Store for the Stars, are presented in an easy-to-understand and interesting way and are intended to teach kids facts about various science subjects. For example, Crystal Radio kits are very popular and consist of one project; build a crystal radio. While they work on this project, kids learn about electronics and electricity, and how radios function.
The gram stain reaction of L. interrogans is gram negative. To stain this bacteria you must use a relatively new staining technique termed immunofluorescence which uses a ultraviolet light to identify its staining. You can also use an older technique that is very time consuming, which is silver staining.
investigators take from the crime scene. With scientific methods it helps investigators to produce a