Eppendorf tubes

Weigh 20 g of the plant sample into an Erlenmeyer flask and add 40 mL of 1 N HCl and 160 mL of acetonitrile. Shake the flask for 30 min at 300 strokes min using a shaker. Filter the aqueous acetonitrile extract through a No. 4 Kiriyama funnel filter paper. Wash the residue on the filter with 100 mL of acetonitrile. Combine the filtrates and remove acetonitrile with a rotary evaporator. Transfer the residue with 20 mL of saturated aqueous sodium chloride solution into a separatory funnel, extract the solution with 3 x 30 mL of n-hexane-ethyl acetate (9 1, v/v), and collect the organic phase in a flask. Dry with anhydrous sodium sulfate and remove the combined organic phase with a rotary evaporator. Transfer the residue into the Eppendorf tube with a... 

Pass 0.5 mL of the suspended acetone solution through the Bond Elut SCX (100-mg) cartridge and collect in an Eppendorf tube. Wash the cartridge column with two portions of 0.5 mL of acetone and combine all of the eluates (total volume ca 1.5 mL). This step is omitted for water. 

Add 150 ]xL of the acetylating solution [triethylamine-acetic anhydride (2 1, v/v)] into the Eppendorf tube and allow to stand for about 30 min at room temperature. Concentrate the reaction mixture under an N2 gas flow at about 40 °C. Add 1 mL of 0.1N HCl to the residue and extract the solution with 3 x 0.5 mL of n-hexane-ethyl acetate (4 1, v/v). Concentrate the organic phase under an N2 gas flow at about 40 °C. 

Add 2 X 0.5 mL of n-hexane-ethyl acetate (9 1, v/v) to the residue and apply to the Bond Elut SI (100-mg) cartridge column. Pass the elution solvent [1 mL of n-hexane-ethyl acetate (3 2, v/v)] through the cartridge and collect in an Eppendorf tube. Concentrate the eluate under an N2 gas flow at about 40 °C and dissolve the residue in 0.5 mL of acetone. Dilute an aliquot of the acetone solution twofold with acetone and adjust the amount of impurities in both the standard and sample solutions for high reliability of GC analyses [details are shown in Section 3.3.4(1)]. 

The WCE is clarified by two successive centrifugations at 16,100 for 2 and 10 min at 4°, respectively, using an Eppendorf F 45-24-11 rotor in a table centrifuge. After each centrifugation, the supernatant is carefully transferred to a new precooled Eppendorf tube, avoiding the lipid layer, and the total protein concentration (mg/ml) is estimated using the Bradford method (Biorad). 

To quantitate the amount of 35S-methionine/cysteine incorporation, the medium is removed, the cells washed with PBS, and overlaid with 250 /d of warm trypsin. After a 4-min incubation at room temperature (which is sufficient to detach the cells, as verified by microscopy), the trypsinized cells are transferred to a 1.5-ml Eppendorf tube, and centrifuged at 2000g at 4°. The supernatant is carefully removed after centrifugation and the cells are placed on dry ice for 5 min. 

The next day (48 h posttransfection), the medium is replaced with fresh DMEM containing different concentrations of compound (nM—fiM concentration range). After 12 h of incubation, the cells are washed with PBS, 40 1 of luciferase lysis buffer [100 mM KxP04 (pH 7.8), 0.2% Triton X-100] is added to each well, and the plate is incubated for 15 min at room temperature with gentle rocking. The cell extract is transferred into Eppendorf tubes and kept on ice. 

Sterilize gold or tungsten particles (Bio-Rad, USA) of around 1 pm diameter with 70% ethanol followed by several washes with sterile water in an eppendorf tube. After the last wash, pellet the particles, discard the supernatant, and resuspend the pellet in 50% glycerol to have a final gold concentration of 60 mg/ml. 

Add50mL of membrane preparation to 50 pLIDP mix in an Eppendorf tube. 

Centrifuged the suspension at 7000g for 5 min in an Eppendorf tube containing a carbon plate prepared according to the method of Tanaka... 

Fig. 4.3 Behavioral bioassay by using a felinine derivative. Felinine purified from cat urine by HPLC was dissolved in water at a concentration of lOmg/ml, and 200 pi of the solution was stored in a 1.5-ml eppendorf tube at room temperature for 5 days. GC-MS analysis detected 3-mercapto-3-methyl-l-butanol in the headspace gas of the tube. The cat (6-year-old castrated male) was able to sniff the opening of the tube, but not contact the felinine solution. The cat sniffed 3-mercapto-3-methyl-l-butanol with considerable interest (18s and 25s) and then licked his lips five times (37 s)...

After the experiments, the Prototype Unit was disassembled and the component parts were individually swabbed with sterilized cotton wools (4 cm2). Each samples were stored in 1 ml sterilized distilled water in an eppendorf tube. 50 pi of sample was transferred to TSA and MEA plates. The TSA plates were incubated at 37 °C for 24 h and bacterial colonies were counted. The number of fungal colonies was determined from the MEA plates after incubating at 30 °C for 5 days. The results show no viable bacterial and fungal colonies were present in the interior parts of the Prototype Unit. Viable colonies are found on the external surface of the unit. This suggests that air passing through the Prototype Unit was sterilized by the action of the formulated catalyst. 

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

Take a defined amount of Sample in an eppendorf tube. 

Transfer equal amounts of proteins to be immunoprecipi-tated into a fresh eppendorf tube. 

Note Avoid exposing the cel Is to I ight as much as possible from step 15 onwards. For suspension cells carry out the staining protocol in an eppendorf tube till step 10. To adhere the cell... 

Proteinase K (Eluka) or Pepsin (Boehringer Mannheim Biochemicals, Indianapolis, IN) for stock solution 10 mg Proteinase K, 10 mL IX DEPC-treated PBS mix and store 1-mL aliquots in RNase-free Eppendorf tubes at -20°C. 

Select slides with optimized proteinase K digestion and follow the steps below for DNase digestion. Prepare in an Eppendorf tube 1.0 pL RNasin (RNase inhibitor), 11.5 pL UV-irradiated dH20, 37.5 U DNase (RQl RNase free DNase, Promega Inc., Madison, Wl)/(1 U/pL) Total (per slide) 50.0 pL. 

RNase-free Eppendorf tubes are available commercially. Alternatively, soak regular Eppendorf tubes overnight in DEPC-containing distilled water. Next day, drain the water and place the tubes in a beaker or a glass jar and autoclave. Place the jar in an oven dryer at 80°C for 4-5 h. 

UV-irradiated, double-distilled water (U V-ddH20) Filter autoclaved double-distilled water through 0.22-pm filter. Transfer 1 mL to 1.5-mL capacity RNase-free Eppendorf tubes. Without closing, expose them to UV irradiation for approx 30 min. Close the tubes inside the UV station. Store in -20°C freezer (make approx 20 tubes). 

Mix the protein solution and the crystallizing agents in an Eppendorf tube. (If quantities are very small, mix on a... 

Mix the protein, crystallizing agents, buffer, etc., and the freshly made gel solution in an Eppendorf tube or on a coverslip. The gel solution should be at a final concentration of at least 0.2% (v/v). 

Equipment PCR machine, scintillation counter, tabletop centrifuge, temperature-controlled water baths, equipment for horizontal and vertical electrophoresis, UV-illuminator, phosphor imager, automatic DNA sequencer, vacuum dot-blot manifold (Schleicher and Schuell). PCR 0.5 ml hot-start mbes, aerosol resistant pipette rips, autoclaved Eppendorf tubes (all from Fischer Scientific, Brightwaters, NY) and glassware, diethyl pyrocarbonate (DEPC, Sigma)-treated solutions. 

Mix 4 mg of KLH or a respective amount of a glycerol-containing solution of KLH (volume maximal 60 pi) with 190 pi Soln. A. Weigh 0.6 mg Traut s reagent (2-iminothiolane) into an Eppendorf tube and add the carrier protein solution. Shake at RT for 30 min. 

Weigh 4 mg of a monochloroacetylglycyl peptide (MCA-Gly peptide, peptide carrying a MCA-glycyl residue at the N-terminus) into an Eppendorf tube and add the activated KLH or other iminothiolane-activated carrier protein. Shake vigorously at RT for 3 h. Dialyze the reaction mixture twice at RT against PBS for 1 h each. Calculate protein concentration from 235-, 260-, and 280-nm readings (cf. Protocol 1.1.7). 

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