The mordant help the dye bite onto the tissue, so that it would hold fast during washing. The decolorizing cell by alcohol causes this thick cell wall to dehydrate and shrink and the closed the pores of cell can prevent the stain from exiting the cell. Hence, the complex still remains in the Gram positive bacteria even after decolorizing and Gram positive cells will be stained a purplish-blue colour. This is because the cell walls of Gram positive organisms include a thick layer of protein-sugar complexes called peptidoglycans which makes up 60-90% of the gram positive cell wall. However, the cell walls of Gram negative bacteria do not retain this complex when decolorized.
Place a titration (receiver) flask containing 4% boric acid and two drops of methyl red dye indicator into the unit. Distillation takes place for 9 mins. After the digestion has been completed the digestion flask is connected to a receiving flask by a tube. The solution in the digestion flask is then made alkaline by the addition of sodium hydroxide which converts the ammonium sulfate into ammonia gas. The ammonia gas that is formed is liberated from the solution and moves out of the digestion flask and flows into the receiving flask which contains an excess of boric acid.
The culture was then streaked on Asbhy’s N-free agar plates and incubated at 37 ºC for 24h. Production of ammonia by the isolate was quantified by the method of Goswami et al. (2014). Bacterial culture grown in Asbhy’s N-free liquid medium was centrifuged at 6000 rpm for 10 min and 0.2 ml culture supernatant was mixed with 1ml Nessler’s reagent and total volume was made 8.5 ml by adding ammonia free distilled water. Development of brown to yellow colour is indicative of ammonia production.
Then, the flask is put on shaker table and mixed at 150 rounds per minute before allowing them to settle for 10 minutes. After settling, the water sample is poured from side spout which is connected to the bottom of the flask. Some researchers reported better reproducibility with modified flask where stopcock is installed at the bottom of the flask, instead of side spout to pour the water sample (Blondina, et al., 1997) (Sorial, et al., 2004a) (Sorial, et al., 2004b). The dispersed oil in the removed water sample is extracted into methylene chloride for further analysis. Then, the oil concentration is evaluated using 340, 370 and 400 nm light absorbance (Environmental Protection Agency,
3.3.4 Preparation of CaCl2 solution The molecular weight of CaCl2 was 111 g/mole. Weighed 11.1g CaCl2 and dissolved into 100ml distilled water. The final CaCl2 concentration would be 1M. CaCl2 solution was used to make bottom agar and initiate the infection cycle. 3.4 Selection of most sensitive strain to bacteriophages to make new stock culture Starting culture was prepared by inoculating 1ml (1×109 CFU/ml) stock Lactococcus lactis ssp.
MATERIALS AND METHODS Bacterial strains and culture conditions Two S. aureus strains were used in the present study; S. aureus 8325-4 (SigB-) and SH1000 representing a SigB+.strain. Overnight cultures were grown in Luria Broth (LB) at 37°Cwith shaking at 150 rpm. Exposure to antibiotics was carried out as detailed below. Antibiotics Ciprofloxacin were purchased from Sigma-Aldrich CO. 10 mg/ml stock solution of antibiotic were prepared freshly with 0.1N HCl and stored at -20°C. During the experiment we diluted with sterile water 1:10 and 1:100 depending on the different drug concentration.
Flow rate A: .010 mL/min b. flow rate B: .010 mL/min c. Flow rate C: 1.000 mL/min 11) Click download and turn detector off, leave computer and pumps on FT-Raman Method 1) Fill the blue dewar with liquid nitrogen and wait 20 minutes then top off 2) make sure the FTIR is on 3) Turn on the laser power supply switch and then turn the key to the on position 4) Make sure the lever between the Raman and FTIR is up, the lever between the Raman and microscope is down, and the internal lever in the Raman should be up, meaning bypass closed 5) Double click on the Varian Resolutions Pro icon to open software 6) From the current scan menu select Raman scan 7) Optics parameters should be: a. IR source: off b. Beam: right c. Detector: Raman Ge d. Beamsplitter: quartz near IR e. Accessory: FT-Raman f. ATR Crystal: none g. Optical filter: holographic notch h. Aperture: open 8) Select the laser tab and click turn on diode 9) Press the shutter switch on the front of the Raman (to open) and turn the power to its highest,
After 10 minutes a purple liquid should remain. Equal amounts of 150ml was poured into 7 different glasses using the coffee filters to ensure no large cabbage piece go into the solution. Various household items with varying pH levels was poured into each glass namely; vinegar, lemon juice, ENO, baking powder, hand sanitiser, handy andy and water. Each of these items were measured to 50ml of each sample and was added to each individual glass and the colour changes were recorded. The neutralisation experiments were then conducted by adding a base to an acid-indicator solution or by adding an acid to a base-indicator solution to make a neutral purple solution.
To prepare a shelf stable product, the beetroot cubes were dehydrated up to final moisture content 9±1% (w.b.) (Singh, Kingly, & Jain, 2007) at an air temperature of 55, 65, 75 oC and air velocity of 1.6 m s-1.Inital moisture content was determined by the oven drying method, for the natural and osmosed Beetroot samples at a temperature of 1350C for 2 hours until constant weight was reached 1 with repetition in order to assure moisture content average
These plates should be pre-weighted previously, pipette out 10 ml extract for each petri plate from the respective conical flask and dried till the solvent loss. 10 ml of extract solution contain = X gram extract 100 ml of extract solution contain = X 100/10 =10X gram extract 2 gram powdered drug contain = 10X gram extract 100 gram powdered drug contain = 10X × 100/2 gram extract = 500X % X = difference in pre weight and final weigh Ethyl acetate