Turner fluorometer

Turner fluorometer model 111 with adaptation for TLC (Firm 33) cf also Camag-information QTL-65 and QDC-6-65 (Firm 33). 

Extracts obtained as described in IV.3.I are measured fluorometrically with the Turner fluorometer. 

See 1V.3.I,C but only glass filters should be used. The Turner fluorometer is fitted with the high sensitivity door, F.4T4-BL lamp, Wratten 47B or Coming CS.5-60 filter for the excitation light and Corning CS.2-64 filto for the emitted light. 

The extracts from 0.25-2 liters, obtained exactly as described in IV. 3.1,F. 1-5, but using only 10.0 ml of 90% acetone, are measured in a Turner fluorometer with the scale zeroed for each door opening against a tube of 90% acetone. Provided that phaeo-pigments are absent ... 

This method derives from a report C. J. Lorenzen Deep-Sea Res., 13 223, 1966) with some further work reported by one of us (Strickland, Deep-Sea Res., In Press). Sea water is pumped toough a cuvette in a specially sensitive Turner fluorometer and the fluorescence of the living plankton cells measured directly. The method is an invaluable semiquantitative tool for measuring the surface concentration of phytoplankton in a ship underway but requires very frequent standardization if it is to be used as a precise technique in eutrophic waters. No generally applicable precision can be quoted. The method will measure between about OjOS and 20 mg chlorophyll a/nP. Greater quantities (such as found in red-tide blooms) can be handled if a specially constructed door 1 is made with a very small hole. 

A Turner fluorometer, Model HI with a flow-through door and cuvette (f-inch orifices). Use a high intensity F4T.5. blue lamp with a blue Coming filter CS.5-60 for the excitation light and a red Coming filter CS.2-64 for the emitted light. The standard photomultiplier must be replaced Ity a red sensitive one (R136). 

The particulate material from a sample of sea water, filtered onto a membrane filter, is extracted repeatedly with acetone, trichloroacetic acid, and ethanol. The residue is allowed to react with 3,5-diaminobenzoic acid and fluorescence of the solution in perchloric acid is measured by the Turner fluorometer. 

In ecological studies on particulate materials in aquatic environments it is often useful to have a method available which can give a rapid indication of the in situ occurrence of maxima in particle concentrations. For this purpose we have employed a G. K. Turner fluorometer as described by Stephens (Deep-Sea Res., 14 465, 1967). The advantages of this instrument are that it is easily maintained, it is readily adapted to automation, and it is complete without an outboard sensing device. 

G. K. Turner fluorometer fitted with a F 4T5 blue fluorescent light. 

Chlorophyll concentrations were estimated from 40 ml subsamples following Suzuki and Ishimaru (1990). Samples were filtered on Whatman GF/F glass-fibre filters (pore size 0.45 pm). Chlorophyllous pigments were extracted by direct immersion of the filters in 5 ml of N,N-dimethylformamide, and actual extractions were made in the dark at 20°C. Concentrations of chlorophyll a in the extracts were determined following Strickland and Parsons (1972) using a Turner 450 fluorometer previously calibrated with chlorophyll a extracted from Anacystis nidulans (Sigma Chemicals, St Louis). 

Each sample to be analyzed was dissolved in tris(ethylenediamine)cadmium dihydroxide (1 mL) by stirring overnight, and then water (1 mL) was added. A 1-mL aliquot (concentration < 1.0%) was applied to the column, and elution proceeded with a pressure head of 100 cm and flow rate of 10 mL/h. A Turner 111 fluorometer (excitation filter 2A plus 47B and emission filter 8 plus 65A) fitted with a flow-through door allowed for automatic continuous monitoring of carbohydrates as they were eluted. Relative fluorescence was automatically recorded on a linear strip recorder. Fractions of 3 mL were collected on a FC-80K Gilson microfractionator. Typically, each sample was analyzed several times, usually at different concentrations, to ensure the reproducibility and accuracy of the data. A calibration run using the labeled dextrans was performed a minimum of one time per week. 

Other Parameters Measured Simultaneously with Bioluminescence. Measurements of several other parameters were obtained from the seawater after it had traversed the bioluminescence detector. When working on station with the bathy-photometer, which was equipped with a pressure transducer, temperature and beam transmittance were measured at depth while seawater was pumped by the submersible pump at depth to shipboard with 110 m of 2.54-cm ID hose. Sea surface temperature was obtained continuously from a probe at the intake near the sea chest. The seawater, obtained from either the sea chest or the bathyphotometer, was pumped through a Turner Designs fluorometer to measure chlorophyll fluorescence, and past a pH probe (31) and a conductivity cell when available. Samples of seawater were frozen for subsequent nutrient analysis (NO , NH4OH, P04 , and NO2). Plankton filtrates from 20 to 100 L (depending on plankton abundance) of seawater were collected from a 100-L effluent tank fitted with plankton net collection cups of 20-fxm mesh porosity. The filtrate was split, filtered onto Whatman GF/C 4.25-cm filter discs, and frozen for subsequent carbon and nitrogen determinations. The other half of the sample was preserved in 5% buffered formaldehyde solution for taxonomic analysis. 

Figure 3. Chlorophyll transect obtained from a constant depth tow at 11 m. Key a, raw Variosens data b, the same data filtered with a binomial smootning function having the best-fit value of a = 3,4 s and c, data from the Turner 111 fluorometer where samples are transmitted continuously (5).

The in situ Batfish sampler does not provide seawater samples for on-deck analysis. Therefore, we have also developed a continuous profiling pumping system (11) that measures biological profiles of copepods and chlorophyll and temperature while on station. Copepods and chlorophyll are measured on deck from the hose effluent with a deck-mounted electronic zooplankton counter and Turner 111 fluorometer. Measured profiles of copepods and chlorophyll indicate a vertical resolution of 3-4 m while the pumping system delivers — 50-60 L/min of seawater on deck. 

In vivo fluorescence Turner Designs/Model 10 Double-beam filter fluorometer 1.0% 1 0.02 s to 63% 4 1.0 s to 98% Better than 5 ppt of detection Method Ref. 14... 

Fluorescence was measured with a Turner model 111 filter fluorometer. The excitation filter was a Corning 7-60 (365 nm primary wavelength). The emission filters were Wratten 65-A (495 nm primary wavelength) and 2-A (sharp-cutoff below 415 nm). A digital multimeter was connected to the recorder terminals of the fluorometer to provide digital readout. Fluorescence-quenching (FQ) titrations were performed in batches. Preliminary experiments indicated that quenching was independent of time (at least 26 hours) after 30 minutes. Equilibration times of 60 minutes were used. 

Obviously, a medium-priced spectrofluorometer could have been equipped with a xenon-arc source and used for the analysis, but the filter fluorometer is usually preferred for routine work. In addition, the latter is more sensitive for example, the detection limit for ASA on the Turner spectrofluorometer is 10 M, whereas the detection limit using the Turner filter fluorometer is lO" M. 

Luminescence Spectroscopy. Photoluminescence measurements were performed with the aid of a Fluorolog3 spectro-fluorometer Fl3—22 (Horibajobin Yvon) equipped with double Czerny—Turner monochromators, a 450 W xenon lamp and a R928P photomultiplier with a photon counting system. Cooling down to 10 K was achieved by a closed cycle He cryostat (Janis Research). All emission spectra were corrected for the photomultiplier sensitivity and all excitation spectra for the intensity of the excitation source. To avoid any contamination of water on the sample s surfaces, we carried out the measurements in silica ampules with extreme purity which show no luminescence of the ampules itself. Reflection spectra were recorded on a Cary 5000 UV—vis—NIR spectrophotometer (Varian), which were corrected for both the lamp intensity and the photomultiplier sensitivity. 

Stresser DM, Turner SD, Blanchard AP, Miller VP. Crespi CL (2002) Cytochrome P450 fluoromet-ric substrates identiiication of isoform-selective probes for rat CYP2D2 and human CYP3A4. Drug Metab Dispos 30 845-852... 

Turner, G. K., Associates, 2524 Pulgas Avenue, Palo Alto, California 94303, USA (Fluorometers). 

A 10-mv recorder for the ouQ)ut of the fluorometer with the outyut adjusted as described in the Turner instmment manual is required. 

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