Sample staining

To further investigate the role of the liver in brevetoxin metabolism, PbTx-3 was studied in the isolated perfused rat liver model (27, 28). Radiolabeled PbTx-3 was added to the reservoir of a recirculating system and allowed to mix thoroughly with the perfusate. Steady-state conditions were reached within 20 min. At steady-state, 55-65% of the delivered PbTx-3 was metabolized and/or extracted by the liver 26% remained in the effluent perfusate. Under a constant liver perfusion rate of 4 ml/min, the measured clearance rate was 0.11 ml/min/g liver. The calculated extraction ratio of 0.55 was in excellent agreement with the in vivo data. Radioactivity in the bile accounted for 7% of the total radiolabel perfused through the liver. PbTx-3 was metabolized and eliminated into bile as parent toxin plus four more-polar metabolites (Figure 3). Preliminary results of samples stained with 4-(p-nitrobenzyl)-pyridine (29) indicated the most polar metabolite was an epoxide. 

We note, however, that measurements of protofilaments are not exact. Protofilament diameters are often measured from negative-stain electron micrographs, which may introduce errors and/or variability in size due to drying-induced deformation of the sample, sample-stain interactions, and variable staining (Chapman et al., 1990 Kiselev et al., 1990). Additionally,... 

In order to evaluate binding, uptake, and intracellular localization of targeted drugs via CLSM, nonfluorescent molecules of interest, as well as the appropriate structures of the specimen, have to be labeled with suitable fluorophores. This technique, however, requires a number of preparative steps, including fixation and permeabilization of the sample, staining and counterstaining, as... 

Gel electrophoresis provides a simple method for separating complex protein mixtures. Because proteins are visualized using stains that may not be linearly incorporated in the gel, the intensity of the stained bands may be poorly correlated with the amount of protein. For this reason, gel electrophoresis is at best a semiquantitative technique capable of generating relative purity results. In CE, separations are commonly performed in free solution, i.e., in the absence of any support such as gel matrices. This allows the replacement of the capillary s content in between analyses and therefore the automation of the process. The use of UV-transparent fused-silica capillaries enables direct on-line optical detection of focused protein zones, eliminating the requirement for sample staining. The detection systems available to CE provide true quantitative capabilities. 

Fig. 3. Bpoxy heterogeneities as a function of amine curing agent content determined by two different methods. The upper series were microtomed samples stained with osmium tetroxide and the lower series were plasma treated fracture surfaces. Both methods gave size and distribution values for the heterogeneities which agreed qualitatively...

Run the stained bead preparation on the flow cytometer m parallel with the cell samples stained in the same experiment (see Note 14). 

Analyze the FSC and SSC signals of a sample stained with CD45-FITC/CD14-PE. 

Analyze a sample stained singly with an FITC-labeled antibody, for example, anti-CD8. 

FLUORESCENCE OF CELLS IN SCATTER GATE ON SAMPLE STAINED FOR CD8... 

Figure 7.6 Flaky skin mouse skin samples stained by a standard H E method. (A). The water-treated skin section shows marked hyperkeratosis, mild parakeratosis, modest acanthosis, elongated rete ridges, and modest dermal inflammation, consistent with psoriatic-like dermatitis. B. The water-GTE-treated skin section shows slight hyperkeratosis, no parakeratosis, mild acanthosis, no elongated rete ridges, and mild dermal inflammation (100x magnification).

Fig. 2. AO activity zymograms from mycelium cells of YR-1. The 164,500 supernatant of mycelium cells grown aerobically for 22 h in sMMP media with added different carbon sources was electrophoresed using 6% acrylamide. AO activity was developed in the gel with hexadecanol as substrate. (A) Lane 1, sMMP-hexadecane lane 2, sMMP-hexadecane lane 3, sMMP without carbon source lane 4, sMMP-glucose lane 5, sMMP-glycerol. In all cases 300 (g of protein was loaded in each lane. (B) Protein patterns of samples stained by Coomassie blue R-250. Lane 1, sMMP-hexadecane lane 2, sMMP without carbon source lane 3, sMMP-Glucose lane 4, sMMP-glycerol. One hundred micrograms of protein was loaded in each lane. Arrows show the bands of AO activity.

Advantages of direct immunofluorescence include shorter sample staining times and simpler dual and triple labeling procedures. In cases where one has multiple antibodies raised in the same species, for example two mouse monoclonals, a direct labeling may be necessary. 

In our discussion of sample staining for TEM analysis, we mentioned that lead citrate was sensitive to CO2. What is the balanced reaction for generation of the side-product ... 

Bentonite is a crystalline, claylike mineral, and is available as an odorless, pale buff, or cream to grayish-colored fine powder, which is free from grit. It consists of particles about 50-150 pm in size along with numerous particles about 1-2 pm. Microscopic examination of samples stained with alcoholic methylene blue solution reveals strongly stained blue particles. Bentonite may have a slight earthy taste. 

Sample staining buffer (0.1% (w/v) NaNj and 1.0% (w/v) bovine serum albumin in Hanks balanced salt solution)... 

Wash the cells two to three times with sample staining buffer. 

Fig. 5.80 Mouse kidney sample stained with Alexa Fluor 488 WGA, Alexa Fluor 568 phalloidin, and DAPI. Recorded with two detectors connected to one TCSPC channel. Left 488 nm channel, right 535 nm channel. Colour represents lifetime, hlue to red = 750 to 2,250 ps. From [37]...

Fig. 5.84 Mouse kidney sample stained with Alexa Fluor 488 wheat germ agglutinin, Alexa Fluor 568 phaUoidin, and DAPI, recorded hy four detectors connected to separate TCSPC channels. Left Lifetime image the colour represents the amphtude-weighted mean lifetime, hlne to red = 0.7 to 1.7 ns. Right Colour represents the amplitude of the fast hfetime component, hlne to red = 0.1 to 0.9. From [39]...

Fig. 1. Set up for sample staining and washing. Materials for cell staining, washing, and mounting coverslips are shown.

Data are analyzed by flow cytometry analysis software (BD FACS Diva, BD Biosciences Flowjo, TreeStar). Data presentation using the frequency of positive events is appropriate only in presence of a bimodal distribution of the emitted fluorescence. In this case, there is no particular preference for the use of the histogram or the dot plot to present data. In case of a non-bimodal distribution of the emitted fluorescence, data should be reported as relative MFI (i.e., the ratio between the MFI values of the sample stained with aU the experimental markers and the MFI values of the negative control sample) and the histogram layout should be preferred. Differently from frequency data, this analytical approach provides relative quantitative information of the chemokine receptor expression levels on the surface of each... 

The degree of nanotube dispersion in polymer matrix was studied with transmission electron microscopy (LE0912 AB OMEGA, Germany). Microscopic sections with 70-100 nm width prepared with ultramicrotome Reichert-Jung Ultracut with diamond cutter at -80°C. Microscopic analysis was made with accelerating potential of about 100 kV without chemical sample staining. 

Porches and decks should be sampled. Stained and varnished surfaces, as well as plaster, could contain lead and should be tested using the same methods. 

Question (3). A shadowed carbon replica of an etched sample contains little or no polymer. If it contains the information required, it is an excellent way of producing a less sensitive sample. Stains by definition increase the contrast of the specimen, but do not necessarily increase the stability of the image. Some stains, such as iodine, are rapidly driven off by irradiation in vacuum while others are completely stable. 

Figure 13.17 Polystyrene-Woc/c-poly(ethylene-sfaf-butylene)-Woc/c-poly(methyl methacrylate) bright field transmission electron micrograph, sample stained with RUO4. Note knitting pattern.

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