Cotton plug

The cold reaction mixture, which may be freed from suspended solid by rapid filtration through a cotton plug, is transferred to a 2-1. or 3-1. separatory funnel, and the aqueous layer is drawn off into the original reaction flask. The ether layer is poured into a 2-1. Erlenmeyer flask containing about 50 g. of anhydrous calcium chloride, and this flask is placed in the ice bath in which the diazotization was run. The cold aqueous layer is then extracted with two 100-ml. portions of chilled ether, which are combined with the first ether extract. After 5 minutes with occasional swirling, the ether solution of adipyl azide (Note 7) is sufficiently dry, and it is poured into a 2-1. round-bottomed flask containing 350 00 ml. of benzene (Note 8). The calcium chloride is rinsed with a 50-ml. portion of ether, which is added to the same flask. 

Flame the neck of the flask and the cotton plug before inserting the plug back in the flask. Also, flame the loop to kill residual microorganisms. 

Prepare spores, fungal conidia/small pellets in Petri dish or cotton-plugged flask, for 48 hours. Harvest the spore in separate flask with media for propagation. Once in the separated flask the concentration of spores has reached to about 3 million per litre. It is now ready to be transferred to a 21 B. Braun biostat fermenter. The minimum volume of harvested spores in the flask is 300 ml. Media must be prepared based on sufficient carbon source... 

Do not insert anything into the ear canal before or after applying the prescribed drug unless advised to do so by the primary health care provider. At times a soft cotton plug may be inserted into the affected ear. 

Ten grams (0.082 mole) of benzoic acid is added to 100 ml. of anhydrous ethanol in a 2-1. three-necked flask equipped with a mechanical stirrer and with loose cotton plugs in the side necks. After the benzoic acid has dissolved, 600 ml. of liquid ammonia (Note 1) is added to the stirred solution. Then 6.2 g. (0.27 g. atom) of sodium is added in small pieces. When about one-third of the sodium has been added, the white sodium salt of the acid precipitates, and there is strong foaming of the reaction mixture. After all the sodium has been consumed, as evidenced by the disappearance of the blue color, 14.6 g. (0.27 mole) of ammonium chloride is added cautiously. The mixture is stirred for an additional hour and then allowed to stand until the ammonia has evaporated. 

Benzaldehyde, suitable for this synthesis, is purified in the following way. A 60-g. (58-ml.) sample is washed with two 20-ml. portions of 10% sodium carbonate and then with water. It is then dried over 5-10 g. of anhydrous magnesium sulfate. A few small crystals of hydroquinone or catechol are added with the drying agent. The dry benzaldehyde is decanted through a cotton plug into a Claisen flask it is distilled under reduced pressure, preferably below 30 mm. 

Reaction progress is monitored by 1H NMR (CDCI3) 0.5-mL of sample is withdrawn periodically (at 30-min intervals after 3 hr), filtered through a cotton plug, and the solvent is removed under reduced pressure. The intergration ratio of proton 4.34 (m, 1 H) (S)-3a, and 5.38 (m, 1 H) (R)-3b is measured and the reaction is terminated when the integration ratio is 1 1. 

Eppendorf tubes (1.5 mLx x 3) cotton plugs for culture tubes and flasks weighing balance pH meter electronic balance autoclave... 

Plug these tubes with cotton plugs and autoclave at 15 psi pressure for 20 min. Transfer a bacteriological loop full of cells from the slants of G. terrae NDB 1165 culture to each of the sterile preculture medium tubes and incubate at 30 °C in a gyratory shaker (180 rpm) for 24 h. 

The resulting solution was filled in 400 mL portions into 25 Erlenmeyer flasks with 2 L total volume equipped with four baffles and in 100 mL portions in five Erlenmeyer flasks with 500 mL total volume equipped with one baffle. The flasks were closed by cotton plugs wrapped in gauze and autoclaved at 121 °C for 20 min. 

Malt extract (1 g), yeast extract (1 g) and magnesium sulfate heptahydrate (0.012 g) were dissolved with water and the volume was adjusted to 100 mL with tap water. The culture medium (30 mL) was placed in a 500 mL shaking-flask with a cotton plug and sterilized (121 °C, 20 min). The seed culture broth was transferred to a 500 mL shaking-flask containing 30 mL of the culture medium. Cultivation was carried out for 48 h at 28 °C and 115 strokes per minute. 

Fill ear insert a moist cotton plug repeat 1-2 h PRN Caution [C, ] Contra w/ perforated eardrum Disp Soln 5.4% antipyrine, 1.4% benzocaine SE Local irritation Interactions May X effects OF sulfonamides EMS None OD Unlikely, may be harmful if swallowed... 

Traces of water or acidic impurities can lead to the formation of insoluble, hydrated lanthanide adducts, or of paramagnetic lanthanum oxide80, adversely affecting spectral resolution. Careful purification of the solvents and substrate is advised, and filtration of the solution through glass-wool or cotton plugs may be useful. 

The submitters used a 10-mL, pressure-equalized addition funnel [containing a cotton plug, calcium hydride (ca. 3 g, lumps), and sea sand (ca. 1 g)] in place of the Soxhlet extractor. The submitters employed calcium hydride (ca. 1-10 mm, No. 068-34) purchased from Nacalai Tesque, Inc. Alternatively, 4A molecular sieves can be used h place of calcium hydride. 

Ten grams (0.03 mole) of antimony(III) sulfide is poured into the ampul with the aid of a suitable funnel. After the inside of the constriction has been cleaned with a cotton plug, the ampul is connected to a vacuum system, evacuated, and sealed off. During this operation the level of the liquid nitrogen should be corrected from time to time to avoid thawing of the acid, which would immediately react with the antimony(III) sulfide. 

Sterilization After a suitable culture medium is selected for the cultivation of a specific microorganism, it is poured into a culture vessel. If you use test tubes or flasks as your culture vessel, the ends of test tubes or flasks should be covered with a suitable closure to allow for the exchange of gases with the atmosphere, yet to keep foreign organisms out of the media. Various types of closures are used in the modern laboratory including cotton plugs, plastic foam, screw caps, metal caps, and aluminum foil. 

Aspirate a 0.5 cm column of sperm into the French straw then aspirate additional air until the column of CPM without sperm contacts the PVA powder in the cotton plug. 

Cut off the sealed end of the straw opposite the cotton plug. Using a metal rod, expel the sperm from the straw into the 250 jlL IVF drop. 

Dilute the dark green reaction mixture with 10 mL EtOAc and filter through a Pasteur pipette packed with a cotton plug and a layer of sand (and layer of Celite, optional). Direct the filtrate into a separating funnel charged with 1 M... 

---