What is the principle of Phenylalanine Deaminase Agar Slant Test?
110963
The purpose of this test is to determine an organisms ability to remove an amine group from the amino acid phenylalanine using the enzyme phenylalanine deaminase.  These bacteria include Proteus, Providencia, and Morganella of the family Enterobacteriacea, and some species of Moraxella.\nPhenylalanine is in the agar.  When an organism that can deaminate it is inoculated onto the agar the phenylalanine is converted into phenylpyruvic acid.  This acid reacts with an added ferric chloride reagent to give a color change to dark green (indicates a positive test). No color change after adding ferric chloride is a negative test.
750656
Read this...see source for more:\n\nSource 1:\n\n\nTRI-CHEK Buffer Sets provide calibrated and pre-weighed amounts of buffer powders at three pH values pH 4.0, 7.0, and 10.0. A correctly calibrated pH meter will check all three points. This set furnishes the materials needed for reliable pH meter standardization and verification.\n\nThe buffer powders in the package are stable and will keep indefinitely. The powders dissolve rapidly in water to give fresh reliable standards in just a few minutes.\n\nThe Color Keyed Buffer Preservative, included in the sets will prolong the useful life of the solution. A few drops of this preservative added to the buffer solutions is an effective mold inhibitor and automatically tints each solution to its own value color.\n\n    * Tri-Chek Capsule Set includes one vial of ten capsules each for pH 4, 7, and 10 buffers\n    * Tri-Chek Chemvelope Set includes three pouches each for pH 4 and 10, four pouches for pH 7\n    * Tri-Chek sets also include dispensing vial of Color Key/Buffer Preservative; add to buffer to inhibit mold and to color-code solution: red-orange for pH 4, green for pH 7, blue for pH 10 Tinted buffers change color if contaminated\n\n\n\nSource 2:\nTo maintain good health the body is constantly seeking to get rid of the excess acids that irritate the tissues and deplete them of minerals. One of the principal systems it uses for this purpose is the renal system (kidneys). The normal rate of acid excretion through the kidneys gives urine a pH that falls between 6.75 and 7.25. By testing the degree of acidity of the urine, you can determine whether your body is eliminating a normal quantity of acids. If the acid excretion rate is higher than normal, the urinary pH will be more acidic. This low urinary pH is also an indication that the body is saturated and therefore in an acid state.\nAnother indicator of the overall pH balance in your body is the pH of your saliva. When your body has the mineral reserves that it should, the abundance of minerals will show up in a saliva ph test as a pH reading of 7.0 to 7.50. A low saliva pH reading indicates that the mineral reserves in your body are low, and are being used to buffer acids elsewhere in the body.\n\nThere is a strong correlation between the pH of the body's internal environment and that of the urine and saliva: urine and saliva become acidic when the body's internal environment becomes acidic. You can discover the pH of these fluids by using Alkalive™ pH Stix™. These pH test strips are made specifically to test saliva and urine, and are the most accurate and economical test strips on the market.\n\nDon't trust your body to just any chemical lab litmus pH paper.\nAlkalive™ pH Stix™ are unlike most pH test strips or pH papers on the market. Due to the narrow range in pH of these bodily fluids (generally 5.8 to 7.6) it is imperative that a pH test strip give a clear indication in small pH unit increments. Ours do. Our test strips give an indication in .25 pH unit increments, and test a range of 4.5 to 9.0. Plus, pH Stix use the double color indicator method, allowing for a more accurate determination of the pH value of what you are testing. Throw away the pH paper, and pick up the pH Stix.
350998
It's the least reactive. It's non-polar. It's pKa is simply the average of the N and C terminus. It's also Ambivalent, meaning it can be inside and outside a protein. Because of these properties, if it was replaced with a polar AA, it would change the protein property, and in 99% of time, change in AA is deleterious.
845828
Here you go...\n\nhttp://home.planet.nl/~skok/techniques/laboratory/pka_pkb.html
197713
Adenosine deaminase (ADA) is involved in the proliferation and differentiation of T lymphocytes. Live intracellular organisms, cause the activation of T lymphocytes. Hence with chronic intracellular organisms, ADA levels in pleural/ ascitic fluid will increase.\n\nThe sensitivity and specificity for detection of tuberculous pleuritis with the use of ADA as a marker in the pleural fluid are each >90% (Roth BJ. Searching for tuberculosis in the pleural space. Chest 1999; 116:3-5). \n\nHowever, high levels of ADA in pleural fluid could be due to other reasons too. High levels of ADA have been associated with pleural fluid lymphocytosis, including malignant conditions (eg, adenocarcinomas, leukemias, and lymphomas) and collagen vascular diseases (eg, rheumatoid pleuritis and systemic lupus erythematosus. All these things would make the test not too useful in countries with low prevalence of tuberculous pleuritis. \n\nAlso, high levels of ADA in pleural fluid should not be used per se, to start treatment against tuberculosis.\n\nTo sum it up, ADA in pleural fluid/ ascitic fluid, is a very good indicator of tuberculous etiology. However, other tests are necessary for the final diagnosis.
447908
Most sugar free sodas and gums in the United States are flavoured with it.  When it breaks down from heat one of the byproducts is formaldehyde, which is not good for people.\n\nIt is also closely related to MSG, which give people migraines.\n\nSometimes it's not labeled in the ingredients, you have to search the label for "contains phenylalanine"
789874
The method may depend upon what type of hydrolysis you performed: acid, base or enzyme.\n\nMost methods would depend upon measuring the increase of reducing sugar in the solution (these are aldehydes).  All of these methods are far more complicated than using the disappearance of the blue-black iodine-starch complex.
602214
It is the color test for the measurement of antibody to T-strain mycoplasma.
125022
General Color Tests for Carbohydrates\n\nCarbohydrates are dehydrated when treated with strong mineral acids under non-oxidizing conditions. The free or potentially free aldehyde or ketonic groups of monosaccharides and certain disaccharides are readily oxidized by mildly alkaline solutions of cupric ions; such as Benedict's reagent ( copper sulfate, sodium carbonate, and sodium citrate ). These carbohydrates are called reducing sugars because they reduce cupric (Cu+2)ions to form cuprous (Cu+1) oxide, Cu2O, a yellow to brick-red precipitate. The aldoses are oxidized to aldonic acids (glucose forms gluconic acid), as well as other products. The ketoses yield a mixture of lower molecular weight oxidation products.\n\nProcedure:\n\nBring in different samples of carbohydrates, such as sugars, starches, fruits, vegetables, cookies rice, pasta, beans etc. \n\nWhen performing the following test, run a control tube for each.\n\nMolisch test: a general for carbohydrates.\n\nTo three separate test tubes, add 10 drops of 1% solutions of glucose, sucrose and starch, and dilute each sugar solution with 2 ml. of water. Add 2 drops of alpha naphthol solution (dissolve 10g alpha naphthol in 100 ml. 95% ethyl alcohol ) to each tube and mix. Incline the test tube and slowly and carefully add 3 ml. of concentrated sulfuric acid down the side of the tube to form a layer below the sugar solution. A purple ring at the interface is indicative of a carbohydrate. Additional tests can be performed on apples, celery petioles, carrots, grapes, and onions. \n\nBarfoed's test: a general test to distinguish between monosaccharides and disaccharides. \n\nTo 5 ml. of Barfoed's reagent (dissolve 66.5g of neutral, crystallized copper acetate in 800 ml. of water and add 6 ml. of glacial acetic acid, and make to one liter ), in separate test tubes, add 5 ml. of the 1% carbohydrate solutions, shake the contents of each tube well, and place all of the tubes at the same time in an actively boiling water bath. Heat for 3.5 min. after the water starts boiling again. Timing is important since a false positive test can be obtained for monosaccharides with disaccharides, if the disaccharides are heated for more than 3.5 minutes thereby breaking down ( hydrolyzing ) to monosaccharides. During this period observe the tubes closely and note any change or clarity of the solutions. A positive test for monosaccharides is the appearance of a red precipitate of Cu2O within 1 or 2 minutes, if no precipitate forms it indicates the presence of a disaccharide. Record the time if a reaction ( turbidity )precipitate occurs. For purposes of comparison, it is helpful to make a control tube with 5 ml. of water in place of the sugar.\n\nBenedict's test for Reducing sugars:\n\nPerform the tests on the 1% carbohydrate solutions. Add 5 ml. of Benedict's reagent and 2 ml. of carbohydrate to a test tube and shake each tube thoroughly. Place all tubes in a boiling water bath at the same time. Heat in the water bath for 5-6 min. and observe what happens. Record any changes in color, in the transparencies and in the formation and color of any precipitate.\n\nAdd 4-5 drops of 3M HCl to 5 ml. of 1% sucrose solution and heat in the boiling water bath for 5 min. Treat the 1% starch solution in the same way but extend the heating period to 25-30 min. Apply Benedict's test to 1-2 ml. of each solution in the same manner as before. Compare the results with those obtained without acid treatment.\n\nBial's Orcinol test distiguishes a pentose ( 5 carbons ) from a hexose ( 6 carbons ) monosaccharide.\n\nPipet 4 ml. of each carbohydrate ( 1% solutions ) into separate test tubes. Add 2 ml. of Bial's reagent ( dissolve 6g orcinol in 200 ml. 95% ethanol. Then add 40 drops of 10% FeCl3.6H2O solution ) followed by 5 ml. of concentrated HCl to all the tubes. Mix and stopper the tubes with cotton and heat in a boiling water bath for 10 min. A positive reaction for a pentos is indicat
275373
MH agar is more stabilized/buffered media so that byproducts of bacteria can not change pH and hence efficacy of antibiotics tested. \nMH is not the only media to test susceptibility, some organisms need more nutrients and Blood Agar is used to test susceptibility.
81025
alkaline potassium permanganate test
888380
You have to have growth to measure the zone. When you put the antibiotic disc on the plate, it creates a gradient of antibiotic concentration in the agar. The growth has to occur to show you what the lethal concentration is. Without any growth, you can do nothing with it. You may want to consider doing it again at 35C instead of 37C. That temperature might be too much for the organism (it does grow on skin usually, so it may prefer a slightly lower temp than body temp). \n\nAs for the concentration, it depends on which antibiotic you are testing. Each antibiotic has a slightly different diameter for sensitive, resistant and intermediate. A table can be found on this high school lab instruction: http://chsweb.lr.k12.nj.us/psidelsky/kirby_bauer_technique.htm
337160
Congrats, I am working on my thesis too.  There is PDA (potato dextrose agar), V8 agar (made from guess what, V8) and many others.  Each is designed for a specific purpose.  I am not an expert on this, but try a search engine.
481137
To clarify how an alien addition and substitution lines works,For it a  greenhouse bioassay was developed that consistently ranked four small grains in their correct order of susceptibility to take-all in the field (wheat > barley > rye = oat) (4). This assay was used to evaluate several wheats that carry alien chromosomes. Single plants were grown in a 1:1 (v:v) mixture of pasteurized soil (Kennebeck silty clay loam) and vermiculite in plastic tubes (2.5 cm in diameter and 12.5 cm long). Experiments included 10 tubes per entry-treatment (inoculated or non-inoculated) per replication and 4 replications. The experimental design was a randomized split-plot with the accessions as main-plot treatments and presence or absence of inoculum as sub-plot treatments .Inoculated tubes each received three oat kernels colonized by G. graminis var. tritici introduced 1 cm below seed level .After 4 weeks at 20±5°C, fresh weights of plant parts (10 plants per treatment per replication) above the soil level were measured and losses in fresh weight calculated.\nFour sets of wheat-alien chromosome addition and substitution lines of species with resistance to take-all were obtained from the Wheat .. The sets were: (i) wheat (cv. Chinese Spring)-Hordeum vulgare (cv. Betzes) disomic addition lines; (ii) wheat (cv. Chinese Spring)-Hordeum chilense disomic addition lines; (iii) wheat (various lines)-H. villosa disomic addition and substitution lines; and (iv) wheat (cv. Chinese Spring)-H. villosa disomic addition lines. Three of the four sets were not complete. Cytogenetic analysis revealed that two addition lines of Set i (chromosomes 1H and 7H) and two addition lines of Set ii (2Hch and 3Hch) had only 42 chromosomes. For Set iii, addition and substitution lines for 1V, 2V, and 7V were not available. Parental lines and "Don" oats were used as controls.Each set of addition and substitution lines, along with the appropriate controls, was evaluated in its own experiment. Within an experiment, 80 seeds of each entry (line or control) were used (10 in non-inoculated tubes and 10 in inoculated tubes in each of 4 replications). All five wheat-barley disomic chromosome addition lines were more susceptible [82 to 90% loss in fresh weight, LSD (P = 0.05) = 10.1] than the barley parent (Betzes = 36%) and two of them (2H and 3H) had significantly more loss (90%) than the wheat parent (Chinese Spring = 78%). In another experiment, there were no differences among all five wheat-H. chilense disomic chromosome addition lines [77 to 88%; LSD (P = 0.05) = 13.7] and they were as susceptible as the wheat parent (79%). In a third experiment (Set iii), H. villosa [30%; LSD (P = 0.05) = 8.16] was more resistant than barley (Betzes = 47%); however, all four wheat-H. villosa disomic chromosome addition and two substitution lines (4V and 5V) were more susceptible (85 to 93% loss) than the wheat check (76%). Substitution lines 3V and 6V were as susceptible (75 to 80%) as wheat. In a fourth experiment involving the complete set of wheat-H. villosa disomic chromosome addition lines (Set iv), improved levels of resistance over that of the wheat parent [77% loss; LSD (P = 0.05) = 14.9] were not detected in any of the chromosome addition lines (74 to 90%).In summary, the bioassay used in this study was a rapid, accurate way for screening accessions for susceptibility to take-all in the greenhouse. None of the addition or substitution lines had improved levels of resistance even though their resistant parents had significantly less take-all than wheat. In the cases where a complete set of lines was not available, any genes that might confer resistance may be on a chromosome missing from the set. Alternatively, take-all resistance in these species may be polygenic with genes on different chromosomes or it may be masked by the wheat genome. Therefore, transfer of take-all resistance from H. vulgare, H. chilense, or H. villosa to wheat may not be easily accomplished.
787723
This test to quantify the inhibition of lipopolysaccharide (LPS) activity by serum with a turbidimetric Limulus amoebocyte lysate assay. Assays are performed in multiwell microplates, and turbidity is measured as the optical density at 380 nm with a microplate spectrophotometer. LPS potency is measured as the 50% maximal Limulus amoebocyte response (LR50) of LPS diluted with saline. By comparing LR50s in saline, LPSs from various species of bacteria are standardized against the U.S. Reference Standard Endotoxin, lot EC-5.  .   A positive correlation is found between standardized potency in saline and serum inhibition of the various LPSs tested.   The degree of inhibition of all types of LPS tested increased are found with increasing serum concentration.\nVR
998779
Ninhydrin, (Triketohydrindane hydrate) is a chemical used to detect ammonia or primary amines. It may be dissolved in a number of solvents, including isopropanol.\n\nWhen reacting with these free amines, a deep blue or purple color is evolved. Ninhydrin is most commonly used to detect fingerprints, as amines left over from peptides and proteins (terminal amines or lysine residues) sloughed off in fingerprints react with ninhydrin.\n\nNinhydrin can also be used to monitor deprotection in solid phase peptide synthesis. When the growing peptide chain is deprotected, a ninhydrin test yields blue. If the next peptide residue is coupled then the test is colorless or yellow.
628104
Nutrient agar is a basic non-selective medium used for growing bacteria generally.\n\nmeat extract 3g\npeptone (bactopeptone) 10g\nNaCl 5g\nagar 15g\ndistilled water 1L\n\nSterilization by autoclaving 121 °C, 20 min.