Bacteria dies at high temperatures so the plates were heated to kill off any lingering bacteria that may have been present on the agar plate. 2. A sterile cotton swab was used as opposed to a regular one because contamination might have
The most common treatment for these infections, caused by Staphylococcus aureus is the antibiotics. There are many kinds of antibiotics using in the modern days, but the first kind of antibiotic being introduced for treating Staphylococcus aureus was Penicillin in 1943. This kind of antibiotic stops the formation of peptidoglycan cross-linkages that makes the bacterial cell well stronger. This eventually makes the cell wall formation and degradation become imbalanced, consequently lead to the cell to die. Other kinds of antibiotic were quick introduced for treating Staphylococcus as well.
Observe after at least 5 minutes. For a closer examination, use the glass rod, popsicle stick or toothpick to hook the precipitate. * Step 6 – Pour the liquids down the sink and clean the rest of the equipment. Read more at Suite101: How to Extract DNA From Fruit and Vegetables: A Home Experiment for Viewing Real Deoxyribonkucleic Acid http://www.suite101.com/content/how-to-extract-dna-from-fruit-and-vegetables-a76806#ixzz1EkVq2LaJ Theory The mashing breaks the cells apart. The detergent breaks them open, freeing the cell contents (including the DNA).
2. Use the sterile cotton swab to create a lawn of P. anvenginosa on 2 of the plates of Mueller-Hinton agar aseptically. 3. Using sterile forcep, pick key lime discs, and place them on opposite sides of a petri dish containing P. anvenginosa, with the code side facing up. Tap them gently with sterile forceps to stick them to the agar.
Determine what your group’s hypothesis will be and write it as an “if, then” statement on your lab report. 2. Label each petri dish with the 4 different amounts of salt using the grease pencil: (control (0%), 1%, 2% and 3%) 3. To make salt concentrations of 1%, 2% and 3%: -Place 100 mL of water in beaker -To make a concentration of 1%, add 1 gram of salt (for
Add 0.2 ml of yeast invertase and incubate at the same temperature for 6 mins. After incubation quench with 8.0 ml of 0.1M H2SO4 and mix thoroughly. Transfer 0.1ml aliquot of sample to a separate test tube and add 0.9 ml of H2O followed by 4ml of WSG and incubate at afore mentioned temperature for a period of 15 mins. The mixture is then assayed at 500nm. Procedure is to be repeated using temperature of 0o, 60o, and 80o C. Introduction Enzymes are single-chain or multiple chain proteins that act as biological catalysts with the inherent ability to promote specific chemical reactions in vivo, as well as in vitro.
Place the pan below #200 sieve. Carefully pour the soil sample into the top sieve and place the cap over it. 5. Place the sieve stack in the mechanical shaker and shake for 3 minutes. 6.
Most differential stains have a challenge step that follows staining with a primary dye. In the Gram stain the challenge step is a rinse with either ethanol or acetone (either may be used). This step dehydrates and tightens the cell wall of Gram positives (mainly peptidoglycan) such that the rinse does not enter the cell. Gram negatives have mainly a lipid cell wall (even though they do contain peptidoglycan) that allows the challenge rinse to penetrate the cell and rinse out the crystal violet-iodine complex rendering the Gram negative cell colourless. Thus, the Gram negative cells must be stained to be seen, and this is done with the counter stain.
Bacterial infections can usually be treated with anti-biotics however some types of bacteria can form a protective spore which can make them more resistant to heat and chemicals. The requirements for optimum growth are is a temperature of 37c, water, food, time, oxygen/ no oxygen. Common illnesses caused by bacteria are Salmonella, tuberculosis, MRSA, bronchitis, ear infections and tonsillitis. Virus-tend to be smaller than bacteria and in order for the cells to reproduce they need to be in a living host. The common way of treating a virus is through immunization as anti-biotics will not be effective against viral infections.
Wasp stings are alkaline, hence acid is needed to neutralise and remove the painful sting. Vinegar (ethanoic acid) is used. Waste from Factories Waste from many factories are often acidic. If this acidic solution is not treated and enters rivers it can kill fish. Slaked lime (calcium hydroxide) is often used to neutralise the acid.