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Why should a petri plate be discarded if media is splashed up the side to the top?
If media splashes up the side of a petri plate, it can result in contamination from the outside environment or other plates. It may also affect the growth of the culture as the splashed media can mix with the top agar layer. To prevent inaccurate results and contamination, it is best to discard the petri plate.
What are the differences between streak plate technique and pour plate technique?
Streak Plate:Pure colonies of bacterial or other microorganisms can be obtained on petri dishes by streak plate. The microbial mixture is transfered to the edge of an agar plate with an inoculating loop or swab and then streaked out over the surface in one of several patterns. After the first sector is streaked in dish, the inoculating loop is sterlized and an inoculum for the second sector is obtained from the first sector. The same is done for third and fourth sector. Thus this is a dilution process. Eventually, very few cells will be on inoculating loop, a single cells will drop from it as it is rubbed along the agar surface. These develop into seprate colonies.Pour Plate:Extensively used with procaryotes and fungi, a pour plate also can yield isolated colonies. The original sample is diluted several times to reduce the microbial population sufficiently to obtain separate colonies when plating. Then small volumes of several diluted samples are mixed with liquid agar that has been cooled to about 45oC and the mixture are poured immediately into sterile culture dishes. Most bacteria and fungi are not killed by a brief exposure to the warm agar. After the agar has hardened each cell is fixed in place and forms an individual colony.
What purpose does the nutrient agar plate serve?
PREPARATION OF NUTRIENT AGAR Bacteriological media come an a wide range of types. Nutrient Agar is a complex medium because it contains ingredients with contain unknown amounts or types of nutrients. Nutrient Agar contains Beef Extract (0.3%), Peptone (0.5%) and Agar (1.5%) in water. Beef extract is the commercially prepared dehydrated form of autolysed beef and is supplied in the form of a paste. Peptone is casein (milk protein) that has been digested with the enzyme pepsin. Peptone is dehydrated and supplied as a powder. Peptone and Beef Extract contain a mixture of amino acids and peptides. Beef Extract also contains water soluble digest products of all other macromolecules (nucleic acids, fats, polysaccharides) as well as vitamins and trace minerals. Although we know and can define Beef Extract in these terms, each bach can not be chemically defined. There are many media ingredients which are complex: yeast extract, tryptone, and others. The advantage of complex media is that they support the growth of a wide range of microbes. Agar is purified from red algae in which it is an accessory polysaccharide (polygalacturonic acid) of their cell walls. Agar is added to microbiological media only as a solidification agent. Agar for most purposes has no nutrient value. Agar is an excellent solidification agent because it dissolves at near boiling but solidifies at 45oC. Thus, one can prepare molten (liquid) agar at 45oC, mix cells with it, then allow it to solidify thereby trapping living cells. Below 45oC agar is a solid and remains so as the temperature is raised melting only when >95oC is obtained. In this experiment each student will prepare 200 ml of Nutrient Agar to be used in Experiment 4. In subsequent experiments, the media ingredients can be found in the Appendix. It is important for you to know how each medium works: what is the energy source? what is the carbon source? what is the nitrogen source? does the medium have selective or differential ingredients? why can only some types of bacteria grow on the particular medium? MATERIALS 1. Electronic or beam balances. 2. Weigh boats, tongue depressors. 3. Tripods, asbestos wire-gauze, asbestos gloves. 4. 10 ml nonsterile pipettes. 5. pH paper or pH meter with standard buffers. 6. 4 13x100 mm screw capped culture tubes. 7. Graduated Cylinder, 250 ml. 8. 2 500ml Erlenmeyer Flasks 9. Beef Extract, Peptone, Agar. 10. 3 N HCl, 3 N KOH. 11. 16 x 150 mm screw cap culture tubes. 12. Nonabsorbent cotton and gauze to make cotton stoppers. Nutrient Agar Beef Extract: 0.3% Peptone: 0.5% Agar: 1.5% PROCEDURE 1. You will be making 200 ml of Nutrient Agar. To weigh out Beef Extract, first tare a tongue depressor, then dip it into the Beef Extract and weigh. Adjust the amount of Beef Extract until the correct amount is obtained. Be sure to be careful not to get Beef Extract on to the balance! You need to weight out enough Beef Extract to get a 0.3% solution. Place the tongue depressor into the flask, beef extract side down. 2. Tare a weigh boat and weigh out enough Peptone and add that to the flask. 3. Add 200 ml of distilled water and swirl to dissolve the peptone and beef extract. Check the pH, it should be 7.0. 4. Tare a weigh boat and weigh out enough Agar and add that to the flask. 5. With a Bunsen burner, tripod, asbestos wire-gauze, heat the medium to boiling to dissolve the agar. CAREFUL: 1) keep the rotating the flasks to prevent the agar from cooking onto the bottom of the flask and 2) watch out: boiling agar can froth and boil out all over the lab bench. As soon as it begins to boil take it off the heat and put it on to the bench. Allow it to cool a few minutes. 6. While the agar is still warm, but not hot, pipette 3 ml each into 4 13x100 mm screw cap culture tubes. 7. Label the flask and your tubes with your name. 8. After preparation of your medium, the instructor will take you to the autoclave. 9. Place your media in the autoclave with those of the rest of the class. 10. After discussion of the parts of the autoclave, autoclave the medium for 20 minutes. 11. The media will be saved and used in Experiment 4.
Does micrococcus luteus grow on msa plates?
Yes micrococcus luteus, along with micrococcus roseus both grow on MSA. But, they do not fermente on this agar giving a negative test. However, Staphylococcus aureus grows on MSA and fermentes giving a positive test. *Side note* MSA plate is used to test for G+ coccus. The plate contains salt and salt "loving" bacteria will grow and show yellow colony, example of S. aureus.
How do homologous pairs of chromosomes line up at the metaphase plate during metaphase II in cell division?
During metaphase II of cell division, homologous pairs of chromosomes line up individually at the metaphase plate, with one chromosome from each pair on either side of the plate. This alignment ensures that each daughter cell receives the correct number of chromosomes during cell division.
Where should a label be written on an agar plate?
Labels should be written on the bottom of the agar plate. Write the label using a marker on the agar side, being careful not to write on the lid or cover of the plate. This ensures that the label remains visible and does not interfere with the growth of microorganisms on the agar surface.
What are the advantages and disadvantages of pour plate method?
Advantages: 1. Counts only living cells 2. Standardized test - used worldwide Disadvantages: 1. 1-2 days of incubation 2. Melted, heated agar 3. Osmotic shock
Why should a petri plate be discarded if media is splashed up the side to the top?
If media splashes up the side of a petri plate, it can result in contamination from the outside environment or other plates. It may also affect the growth of the culture as the splashed media can mix with the top agar layer. To prevent inaccurate results and contamination, it is best to discard the petri plate.
What are the differences between streak plate technique and pour plate technique?
Streak Plate:Pure colonies of bacterial or other microorganisms can be obtained on petri dishes by streak plate. The microbial mixture is transfered to the edge of an agar plate with an inoculating loop or swab and then streaked out over the surface in one of several patterns. After the first sector is streaked in dish, the inoculating loop is sterlized and an inoculum for the second sector is obtained from the first sector. The same is done for third and fourth sector. Thus this is a dilution process. Eventually, very few cells will be on inoculating loop, a single cells will drop from it as it is rubbed along the agar surface. These develop into seprate colonies.Pour Plate:Extensively used with procaryotes and fungi, a pour plate also can yield isolated colonies. The original sample is diluted several times to reduce the microbial population sufficiently to obtain separate colonies when plating. Then small volumes of several diluted samples are mixed with liquid agar that has been cooled to about 45oC and the mixture are poured immediately into sterile culture dishes. Most bacteria and fungi are not killed by a brief exposure to the warm agar. After the agar has hardened each cell is fixed in place and forms an individual colony.
Why does petri plate is inverted during incubation?
Because during incubation moisture will form at the top of the petri dish. Inverting the dish prevents it from dropping into whatever you have in the petri dish.
What are your option for placing a napkin in the setting?
The napkin can go on the left side of the plate, on the plate, above the plate, or on the right side of the plate. Most traditionally the napkin is placed under the fork/forks on the left side of the plate.
What are your options for placing a napkin in setting the table?
The napkin can go on the left side of the plate, on the plate, above the plate, or on the right side of the plate. Most traditionally the napkin is placed under the fork/forks on the left side of the plate.
Why must a straight inoculating needle be used when inoculating an agar deep tube?
This is important to prevent the inoculating needle from becoming stuck in the agar, taking out pieces of agar while trying to remove the instrument. This agar will get into the inoculum when sterilizing the needle on the flame, causing contamination to your sample.
Where is the compliance plate on a 2004 Kia Rio?
On a 2004 Kia Rio, the compliance plate is typically located on the driver's side door jamb. You can find it by opening the driver's side door and looking at the vertical surface of the door frame. The plate contains important information such as the vehicle's VIN, weight ratings, and manufacturing details.
When I am setting the table, do the forks go on the left side of the plate or the right?
Forks go on the left side of the plate.
How should the fork and knife be positioned on the plate?
The fork should be placed on the left side of the plate and the knife on the right side, with the blade facing towards the plate.
Where is the VIN on a clk200 51 plate?
Drivers door - Side plate
