Pasteur Pipets

Pipets, Pasteur and graduated, glass and plastic, serological (1- to 25-ml)... 

PIPET, PASTEUR A glass tube designed for the transfer of liquids. Its unique characteristic is its very fine, long, needle-like delivery tip which allows its use in small tubes. This sharp tip can present a hazard if carelessly handled or disposed of improperly. 

Fig. 11 Experimental set-up for small-scale microwave SPPS of /S-peptides (SPE = solid-phase extraction). 1 Pasteur pipet for N2 agitation 2 10 mL glass vial 3 4mL solid-phase extraction tube 4 DMF 5 coupling solution 6 resin 7 polyethylene frit 8 Luer-lock cap...

Multivesicular Liposomes Kim and his colleages described a method for the preparation of cell size liposomes with high encapsulation efficiency the so-called multivesicular liposomes (Kim et al., 1983). The lipid phase consists of a combination of amphiphatic lipids and a small amount of triglycerides (triolein or trioctanoin) dissolved in chloroform-diethyl ether (1 1). The aqueous phase is slowly added to the organic phase and after vigorous shaking a water-ip-lipid emulsion is formed (Fig. 2A-B). Via a narrow Pasteur pipet the emulsion is subsequently added to a sucrose solution. 

A homemade combination scraper-coUector used in my laboratory can be made from a Pasteur pipet (229 mm x 7 mm OD Fisher Scientific Co., Pittsburgh, PA Catalog No. 13-678-6B) [52]. The pipet is cut with a file 60 mm from the top and 65 mm from the tip to produce a pipet that is approximately 100 mm long, which is then plugged with glass wool. The pipet tip is attached to a vacuum pump or... 

Volumetric glass pipets, various sizes Pasteur pipets, 5.75- and 9-in lengths... 

Electronic analytical balance Volumetric flasks 100- to 1000-mL Volumetric glass pipets, various sizes Pasteur pipets, 5.75- and 9-in lengths Refrigerated centrifuge Nalgene centrifuge bottle, 250-mL Disposable syringes, 5-cm ... 

Rotary vacuum evaporator, water-bath temperature 40 °C Pasteur pipets... 

OmniMixer, with an adapter for a pint Mason jar Pasteur pipets pFi indicator paper... 

Transfer the sample to the column with a Pasteur pipet and drain the solvent to the top of the sodium sulfate layer. Rinse the round-bottom flask three times with 3-mL portions of hexane-ethyl acetate (10 1, v/v), adding these rinses sequentially to the column and draining the solvent to the top of the sodium sulfate layer before the next addition. Discard the accumulated eluate and place a 100-mL round-bottom flask under the column. Elute the residues with 28 mL of hexane-ethyl acetate (10 1, v/v). Evaporate the column eluate just to dryness by rotary evaporation under reduced pressure in a <40 °C water-bath. Reconstitute the sample in 2.0 mL of toluene for analysis (Section 6.2). 

Use a long Pasteur pipette to layer 2.2 ml of the 10% sucrose solution in a Beckman polyallomer tube (14 x 89 mm, 331372). Then, underlay 2.2 ml of the 20% sucrose solution by inserting the tip of the pipette to the bottom of the tube and slowly pipetting the 20% sucrose solution under the 10% solution. Underlay the 30, 40, and 50% sucrose solutions in the same manner. Cover the tube with aluminum foil and store overnight at 4° to establish a linear gradient. 

Harvest the primary antibody solution from the dish using a Pasteur pipet and save. Wash the dish again in BSA-PBS at 4°C five times. 

Load the cell suspension in a Pasteur pipet, and affix the cells to several slides by either of the following methods ... 

Decant all but about 0.2 mL of the supernatant, and resuspend the pellet using a Pasteur pipet. 

Pipet 4 ml of the hot molten Soln. A onto the covered slides laying on a horizontally leveled table. After gelation, punch wells using a stamp as shown in Fig. 4.1. Suck out carefully residual material from the wells using a Pasteur pipette connected to a pump. 

Punch at least two wells of 2- to 3-mm diameter using a Pasteur pipet or a hypodermic needle. The wells are located in the middle of the slide and should have a distance of 5 mm (Fig. 4.3). 

Particularly in the cases of hydroxyacetylenes, the question "How many extractions with Et20 have to be earned out may arise. The following practical tip may be useful. Take a small (2 ml) sample from the extract with a Pasteur pipet and allow the solution to flow along a glass stopper. Further extraction is superfluous when, after the ether has evaporated, no residue is visible on the ground glass. 

To clean a mercury spill, consolidate the droplets with a piece of cardboard. Then suck the mercury into a filter flask with an aspirator. A disposable Pasteur pipet attached to a hose makes a good vacuum cleaner. To remove residual mercury, sprinkle elemental zinc powder on the surface and dampen the powder with 5% aqueous H2S04 to make a paste. Mercury dissolves in the zinc. After working the paste into contaminated areas with a sponge or brush, allow the paste to dry and sweep it up. Discard the powder as contaminated mercury waste. This procedure is better than sprinkling sulfur on the spill. Sulfur coats the mercury but does not react with the bulk of the droplet [D. N. Easton, Management and Control of Hg Exposure, Am. Lab., July 1988, p. 66],... 

In general, solid solutes should be weighed on weighing paper or plastic weighing boats, using an analytical or top-loading balance. Liquids are more conveniently dispensed by volumetric techniques however, this assumes that the density is known. If a small amount of a liquid is to be weighed, it should be added to a tared flask by means of a disposable Pasteur pipet with a latex bulb. The hazardous properties of all materials should be known before use and the proper safety precautions obeyed. 

E Pasteur pipet courtesy of VWR Scientific, Division of Univar. 

Prepare the lipid for chromatography by dissolving 50 to 75 mg of crude lipid in a minimum of hexane (5 to 10 mL). Open the stopcock and allow excess solvent to drain from the column until the level of solvent just reaches the top of the silica gel column. Very carefully add the solution of crude lipid to the top of the column. This should be done by using a Pasteur pipet and allowing drops of the solution to run down the inside of the glass column to the top of the silica gel bed. It is important not to disturb the top of the silica gel column. After addition of the lipid solution, begin to collect a fraction from the bottom of the column into a 25-mL Erlen meyer flask. Set the flow rate to about 2 drops per second. When the level of solution in the column reaches the top of the silica gel, turn off the stop-... 

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