Before placing powders into the aspirator, the jar was washed properly with acetone and then dried. 800ml of solvent i.e. methanol was added gradually. The container with its content was sealed & kept for 20 days with occasional shaking & stirring. The major portion of the extractable compounds of the plant materials were dissolved in the solvent. Then whole mixture was filtered through cotton wool and the filtrate was concentrated by evaporation in dry & clean air.
2-Preparation of nutrient agar plates: Cup –plate method was used for screening the antibacterial activity of pure and dried 100 % ethanol extract .A commercial sample of amoxicillin was used as a standard and nutrient agar was used as culture medium. The natural agar consist of Yeast Extract, Tryptone , Lactose , Manniiol, Sodium Chloride , Dip otassium Hydrogen Phosphate ,Gelatin and Agar .Then , in a conical flask 14g of nutrient agar was mixed into 500 ml of distilled water and , The mixture was stirred and dissolved until most of the agar dissolve. By non-absorbent cotton wool plug the mouth of the flask was closed. By using the autoclave the agar was sterilized for 15 minutes.
The tube was placed back in incubation for 96 more hours to observe any more positives. 2.10 Catalase Test A trypticase soy agar plate was used and after incubation, four drops of 3% Hydrogen Peroxide was added to the plate to flow over the bacterial growth. A presence of bubbling was observed. 2.11 Starch Hydrolysis
We then weighed a filter paper which we will use later in the experiment. We then collected the crystallized acetylsalicylic acid by vacuum filtration in a Buchner funnel and washed the product with a little ice-cold water. We then pre-weighed a clean, empty watch glass and labelled it with our initials and the date, we did this do we could easily identify that it was ours when we go to weigh it with the crystals on. We
Use the following criteria for the preparing of arrange of dilutions in the agar: On the base of steriled petri dish,label each of the concentrations required then place 1ml of the dilutions in water each of them in the labeled dishes after preparing them with the addition of one ml watter in control plate; 19ml pipette containing melted agar is cooled and then added to each plate and mixed together adequately and this mixing is an essential matter. Plates should be dried well after setting them carefully and the lids must be tiped for 20-30 mins.at 37C in the incubator, as the plates inoculated this is done by two methods either as multiple spots of inoculator or by using a platinum or wire loop which is designed for deilevery of 0.001ml over asmall area; the culture shall be diluted in either cases and contains 105to106 organismsml and this is obtained by the addition of 5µl broth culture overnight to 5ml peptone water. Electrolyte deficient and selective media should not be used to avoid giving false results due to the variable effects in the content of the salt on many antibiotic actions.
After experiment on microscope under oil immersion, I learned that my Unknown is gram positive. Under the lens, the bacteria appears in purple color. Its morphology is cocci arranged in cluster. However, during decolorizing process, I put too much alcohol to the crystal violet-iodine complex making the color overly removed. That led to the result of my gram positive has slightly redish
The Another medium used was MAC, it is used to isolate and differentiate gram-negative organisms and it is a pink, dusty rose color. Lastly, the Citrate Slant is a green color and it was used as a differential test to examine enzymes. The media were inoculated at 37°C for 48 hours, then it was observed to determine the
The culture was maintained on a nutrient agar plate/slants at 4°C and as glycerol stocks 40% at −70°C. Preparation of bacterial supernatant for synthesis of nanoparticles A loopful of the culture was inoculated into 250 ml sterile nutrient broth and incubated at 37°C for 24 hours. The
Next, we determined the mass of the penny by placing it on a balance. The mass of the penny was 2.47 grams. Afterwards, we placed the penny in a beaker filled with 20 mL of 6 M HCl. In the end we put the beaker in the fume hood and allowed it to sit overnight. During day two of the penny lab, we removed the penny skin from the beaker using tweezers.
In this lab, genes for a fluorescent green protein (GFP) and antibacterial resistance (ARG) were inserted into E. coli bacteria. E. coli bacteria was resuspended in an ice-cold CaCl2 solution. DNA containing GFP and ARG was added to half of the cells before they were “heat shocked” in an ice bath and hot water. The heat shocking made the bacteria’s cell membrane more porous, so the DNA could enter. Recovery broth was added to the cell suspension, and the bacteria was placed in warm water for about thirty minutes (see Results and Discussion, paragraph 2).
Add another 25cm3 of Methanol and Ethyl acetate to the solutions. Stir gently for 20 minutes using a stirring rod this is to allow more of the active ingredients to mix with the solution. 16. Take two funnels and place one in two separate clean measuring beakers making sure the bottoms of the funnels don’t touch the bottom of the measuring beakers. Take two pieces of filter paper and press one onto each funnel.
The silver ion TLC was prepared through the following procedure: Silver nitrate was dissolved in 10 ml of distilled water. This aqueous solution of silver nitrate was absolutely mixed with 9 g of silica gel (10 ~ 40 μm particles). Then, a 10 × 5 cm TLC plate was coated with the above slurry and activated for 1 h at 90 °C before use. They were immediately transferred into a desiccator in dark for storage after cooling. 32 100 μL of afore-prepared sample solution and the mixed reference standard were diluted 100 times with ethyl acetate.