Staining absence

Ordinary ketones are generally much more difficult to cleave than trihalo ketones or p-diketones, because the carbanion intermediates in these cases are more stable than simple carbanions. However, nonenolizable ketones can be cleaved by treatment with a 10 3 mixture of t-BuOK—H2O in an aprotic solvent such as ether, dimethyl sulfoxide, 1,2-dimethoxyethane (glyme), and so on, or with sohd t-BuOK in the absence of a solvent. When the reaction is applied to monosubstituted diaryl ketones, that aryl group preferentially cleaves that comes off as the more stable carbanion, except that aryl groups substituted in the ortho position are more readily cleaved than otherwise because of the steric effect (relief of stain). In certain cases, cyclic ketones can be cleaved by base treatment, even if they are enolizable. " OS VI, 625. See also OS VH, 297. 

Sputum Cram stain should demonstrate the presence of WBCs and the absence of squamous epithelial cells. It may or may not show a predominance of one type of organism. 

The hypothesis is supported by two additional observations (24). First, mean cell volume for P. brevis in the absence of aponin remained constant for 8 hours, but, in the presence of aponin, a notable increase was observed within an hour and continued for eight hours. Second, Trypan blue (Cl 23850) tests indicated increased cell permeability in the presence of aponin viable, motile cells were only slightly stained swollen cells and cell debris were highly stained. 

Thus the detailed mechanism of peroxide bleaching is not yet finally resolved. It should be borne in mind, however, that the work of Dannacher and Schlenker was carried out at 60 °C on tea-stained cotton, whereas Spiro and Griffith studied the decolorisation of individual colorants at 21-25 °C in the absence of a textile substrate. 

Polymers of methacrylic acid or maleic acid, either alone or as a blend or copolymer with the sulphonated aryl-formaldehyde condensation products, have also been evaluated as stain-blocking chemicals [508,509]. An interesting development is the use of a polystyrene-maleic acid copolymer, this being unusual because of the absence of sulphonic acid groups [508,510]. Although the maleic and methacrylic acid polymers do not have the durability of the conventional syntans, they have the advantage that they are non-yellowing. 

Fig. 6.2. Caco-2 epithelial cell monolayers cultured with T. spiralis L1 larvae in (A) the absence or (B) presence of 1 mg ml 1 rat monoclonal, tyvelose-specific antibody 9D4 (McVay etal., 2000). Monolayers were fixed and stained with trypan blue as described in ManWarren etal. (1997). (A) Serpentine trails of nuclei in dead cells are evident, revealing the paths travelled by larvae. (B) Tyvelose-specific antibody has inhibited the migration of the larva such that it is encumbered in cell debris and has pulled up a large area of the monolayer, creating a plaque (P). Bar = 50 urn. Photomicrograph prepared by C. McVay, TTUHSC, Lubbock, Texas. 

One hour prior to installation of the test substance, both eyes of each rabbit are examined for signs of irritation and comeal defects with a hand-held slit lamp. All eyes are stained with 2.0% sodium fluorescein and examined to confirm the absence of comeal lesions. 

Immunohistochemical stains for kappa and lambda light chains were performed in the bone marrow specimens to determine the presence or absence of light chain preponderance or monoclonality. In all these cases, including those... 

Fig. 10.19 Lack of toxic effects of CM fullerene on breast epithelial cells. Cm does not inhibit cell proliferation. MCF 10A and (A) MDA MB 231 (B) breast cancer cell lines were cultured either in the absence or presence of methanol C60 and cell proliferation was assayed by crystal violet staining. Control, no C 1 Opg Cm, A 50 pg Cm, X 250 pg CM. (C). MDA MB 231 cells were simultaneously stained with calcein and ethidium using a live-dead assay kit. Lack of red-colored cells and the presence of cells stained in green indicate the lack of toxicity (D). MDA MB 231 cells were either untreated (open box) cultured with varying amounts 10 (gray ), 50 (patterned ) and lOOpg (filled ) of C60 for 48 h and analyzed for cell cycle progression by flow cytometry (Levi et al., 2006) (See Color Plates)...

At 24 hours, a strong decrease in the number of topi-positive cells and in topi staining intensity appeared in tumors treated with irinotecan, whereas there was almost complete disappearance of topi staining in tumors treated with edotecarin (Figure 11D). Morphologic analysis of treated samples show absence of mitotic figures after both treatments (mitotic index 2% in controls, 0% in treated samples data not shown). 

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. 

Figure 3.15 Hydrogenase synthesis in regulatory mutants of R. eutropha. Cells were grown on agar plates containing glycerol as the carbon source either in the presence or in the absence H2.The cell material was transferred to filter paper and a triphenyl tetra-zolium chloride-based hydrogenase activity staining was performed. Dark colour reflects activity of the MBH.

The simplest and most sensitive assays for detecting clastogenic (i.e. chromosomal breaking) effects involve the use of mammalian cells. Cultures of established cell lines (e.g. Chinese hamster ovary) as well as primary cell cultures (e.g. human l)nnphocyte) may be used. After exposure to a range of chemical concentrations in the presence and absence of an appropriate metabolic activation system, the cell cultures are treated with a spindle inhibitor (e.g. vinblastine) to accumulate cells in a metaphaselike stage of mitosis. Cells are harvested at appropriate times and chromosome preparations are made, stained with DNA-specific dye and the metaphase cells are analysed under the microscope for chromosome abnormalities. 

Table I. Staining Relative Intensity Observed in Tobacco Stem Sections Incubated with Different Peroxidase Substrates. Transverse sections were incubated with H2O2 and a peroxidase substrate. The oxidation of routinely used commercial substrates was checked in the presence or the absence of ferulic acid salts. Variations of staining intensity in cell walls (— to ++) were judged by observation with a light microscope...

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