Progression staining

PIBCA nanospheres were injected subcutaneously to rats. Autoradiographic pictures obtained after using radiolabelled polymer have shown a progressive staining reduction in the muscular tissue suggesting that nanospheres were slowly biodegraded. In the same study, nanospheres were found to release a peptide (GRF) in a sustained manner. Comparison of the AUC of free GRF and GRF-loaded nanospheres showed that in addition to the slow release process nanospheres were able to improve the bioavailability of the peptide. This improvement could be attributed to the fact that free administered GRF is very quickly metabolized at the injection site, whereas it is partly protected from massive enzymatic degradation when it is administered associated with nanospheres. ... 

Pad Stains. More progressive or higher end furniture finishers add color or pad stains to enhance grain patterns, produce shadows, and create hues found only in exceptionally fine veneers and woods. These pads are appHed at varying levels to create the illusion of the third dimension. 

The progress of the reaction may be followed by analytical thin-layer chromatography on alumina. The submitters used polygram pre-coated plastic sheets (Alox N/UV254) purchased from Macherey-Nagel, Inc. The plates were developed with 1 1 hexane-ether and stained with basic permanganate. The Rf of the product is 0.56. 

Cytokinesis (cell division) in animal cells involves the progressive formation in telophase of a furrow between the two daughter cells in the equator of the mitotic spindle. Immunofluorescent staining of the cortical cytoplasm at the site of the contraction ring reveals an abundance of actin as well as myosin, a-actinin, and filamin (Fishkind and Wang, 1995). Cytokinesis is highly sensitive to actin-myosin inhibitors such as cytochalasin and phalloidin. 

When subjected to the solvents used in tissue processing, immunoreactivity got progressively weaker after each successive exposure to alcohol and xylene, with little change noted after the paraffin. The greatest change in immunoreactivity came at the transition to the completely hydrophobic environment of xylene, probably because it makes it harder to get water back into the protein prior to staining. By the time specimens reached paraffin, heat did little further damage because macromolecules were so drastically modified. 

Progress of Ihe reaction should be monitored periodically during the 2 hr to determine when the starting material is consumed in order to avoid unnecessary heating, which leads to the formation of by-products. TLC can be used 50% ethyl acetate/hexane, silica gel stained with phosphomolybdic acid. 

Beutner, E.H. (1971) Defined immunofluorescent staining past progress, present status, and future prospects for defined conjugates. Ann. NY Acad. Sci. 177, 506-526. 

One of the first applications developed for flow cytometry was cell cycle analysis.2 There are numerous intercalating fluorescent DNA and RNA staining reagents that can be used to determine the amount of DNA in cells, an indicator of cell cycle stage and progression, as demonstrated in Figure 7.3. Nucleic acid dyes may be selective for DNA... 

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)...

The analysis of cell-cycle progression was one of the earliest applications of flow cytometry (for review, see Darzynkiewicz et al., 2004). In this assay, fluorescence signals from cells stained with DNA-binding fluorochromes are plotted as DNA content histograms that may be analyzed by using histogram deconvolution software to quantify cell-cycle phase distributions (Rabinovitch 1994). Fluorochromes that are useful for this purpose are the plasma membrane-impermeant DNA stains, propidium iodide (PI),... 

Dermatitis from skin contact with the chemical usually occurs on the face, especially around the mouth and the sides of the nose the condition progresses from edema, through the formation of papules and vesicles, to ultimate desquamation. The skin and hair of workers handling picric acid may be stained yellow. ... 

Yields sometimes drop when an old bottle of borane-dimethyl sulfide is used. Reaction progress can be monitored by thin layer chromatography (silica gel, eluting with 10 10 1 chloroform-methanol-concentrated ammonium hydroxide). Any remaining phenylalanine stains heavily when exposed to ninhydrin (Rf 0.35). If phenylalanine is detected after 5 hr of reflux, an additional 10 ml (0.10 mol) of borane-dimethyl sulfide is added via syringe, and the solution is heated at reflux for 1 additional hr. 

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