Eppendorf

To obtain the calibration standards, take aliquots ranging from 50 /xL to 300 juL As, from the working standard solution, using an Eppendorf micropipette. Add the appropriate microlitre quantities to the reaction vessel of the vapour generation system, together with 10 mL of hydrochloric acid (AM), delivered from a calibrated dispenser. 

Micro-pipetting instruments such as the "Eppendorf or "Oxford pipettors with disposable plastic cone tips are customarily employed to dispense the liquid samples into electrothermal atomizers. Sampling problems which are associated with the use of these pipettors are among the troublesome aspects of electrothermal atomic absorption spectrometry (67,75). The plastic cone-tips are frequently contaminated with metals, and they should invariably be cleaned before use by soaking in dilute "ultra pure nitric acid, followed by multiple rinses with demineralized water which has been distilled in a quartz still. 

Restek Rtx-IMS fused-silica open-tubular column (FSOT) with integral guard column, 30 m X 0.25-mm i.d. and 0.25-p.m film thickness Eppendorf fixed-volume pipets, 0.50-mL Eppendorf fixed-volume pipefs, 1.0-mL Eppendorf pipel lips, 1.0-mL Amber-glass boftles wifti Teflon-lined caps, 4-oz... 

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)]. 

Eppendorf Netheler Hinz, Cambridge, http //eppendorf.com. 

A special microti ter plate which allows for efficient heat transfer and which can be shaken so as to ensure sufficient mixing was first developed. Accordingly, a commercially available Eppendorf... 

Elution. Incubate the resin for 30 min with rolling in 500 /il Elution Buffer to competitively elute retained proteins. Collect the supernatant after centrifugation at 9300 xg for 5 min at 4° in a microcentrifuge (10,000 rpm in an Eppendorf 5415R). 

The required volume of 50% Ni-silica slurry (7.5 /d/100 ml of starting yeast culture) is equilibrated just before use in buffer BB by two washes each of 500 pi. The resin is collected by centrifugation at 1000 rpm for 2 min in an Eppendorf F 45-24-11 rotor to complete each wash. 

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). 

Approximately 1 mg of total protein is pre-incubated with 25 /il of A-Sepharose beads CL-4B (Amersham Pharmacia Biotech) in 300 /d of binding buffer FLA for 1 h at 4° with gende rocking. The sample is then spun down at 1000 rpm for 3 min in an Eppendorf F 45-24-11 rotor, preserving the supernatant for further use. An aliquot of 3% of the total protein from each reaction is stored at —20° to provide the input reference sample in the subsequent analysis. 

Immune complexes attached to the beads are then spun down at 1000 rpm for 3 min in an Eppendorf F 45-24-11 rotor (preserving a 3% aliquot), and the beads are washed 3 times with 1 ml of HA buffer each. 

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. 

Basic laboratory equipment centrifuge with cooling condition control at 4°C, heat block, pH meter, eppendorf BioPhotometer, microtube, and so on. 

Hybridized spots appear as grey spots in the scan. The darker the spot, the more target DNA is present. Kits based on this technology are currently under development by Eppendorf, Nanosphere and Clondiag. 

Pre-acidified pore water (100 pi, diluted with Millipore Q-water if necessary) was transferred, using an Eppendorf pipette, into a 10 ml volumetric Pyrex flask. To this flask nitric acid (50 pi) was added, and the solution was then brought to volume with Millipore Q-water. Standards were made up by adding various amounts to stock metal solutions (lmg/1), nitric acid (50 pi), and a seawater solution (100 pi) of approximately the same salinity as the samples to be analysed. This final addition ensures that the standards are of approximately the same ionic strength and contain the same salts as the samples. 

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)...

Put grids in Eppendorf microtubes filled with an antigen retrieval solution (10 mmol/1 citric acid, pH 6.0) and heat them in a domestic pressure cooker at boiling point for 2 5 min (Buchwalow et al. 2004, 2005). The cap of the microtube must have a hole bored by a needle in order to prevent the loss of the material in the process of bubble formation when boiled in a retrieval solution. 

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. 

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