Positive staining

The enzyme /i-phenylethanolamine-A-methyl transferase, which is required to convert noradrenaline (NA) to adrenaline (Ad), is present in the CNS and there is histofluoro-metric evidence (positive staining with antibodies to that enzyme and to tyrosine hydroxylase and dopamine /i-hydroxylase as well) for adrenergic cell bodies in two groups (nuclei) alongside NA neurons of the locus coeruleus (EC) but ventral and lateral (Ci) and dorsal and medial (C2) to it. Projections go to the hypothalamus and in... 

The pituitary, as well as the hypothalamic hormones, also contribute to VN development. A transient prolactin receptor (PRLR) is expressed in the late foetal rat. At El8, there is positive staining for this binding protein along the lumenal border the reaction is restricted to the medial (sensory) zone [Freemark et al, Fig. 6(d), 1996]. These sites possibly function in the detection of endogenous lactogenic ligands such as PL-I and PL-II. The VNORs also occupy microvillous sites in this area, but the precise developmental role of PRLR in the early AOS is unknown. The modulatory influence of prolactin is well established after puberty in mammals as a reproductive determinant (Chap. 5). In a more central role, it acts on the EOG recorded from the accessory area of the bulb in newts (Toyoda, 2000). 

Increased silver-positive staining 80 mg/kg, s.c., twice daily, 15-48h Commins et al.68... 

It is well accepted that MDMA produces 5-HT depletions in rat CNS, but much less attention has been devoted to the effects of MDMA on established markers of neurotoxicity such as cell death, silver-positive staining, and reactive gliosis. Support for the hypothesis of MDMA-induced axotomy relies heavily on immunohistochemical analysis of 5-HT levels, which could produce misleading results if not validated by other methods. For example, MDMA-induced loss of 5-HT could be due to persistent adaptive changes in gene expression or protein function, reflecting a state of metabolic quiescence rather than neurotoxic damage. Table 7.3 summarizes the effects of MDMA on hallmark measures of neurotoxicity. 

Although peripheral area of the slide showed a percentage of positive staining about 50%, the central area of the slide showed significantly weak positive result. 

Figure 8.2 Design of protein-embedding barcode is depicted in (a) five thin layers of matrix (the thicker lines) coated with variable concentration of tested protein (thinner lines located above the matrix), (b) A FFPE tissue section of bladder cancer IHC-stained by monoclonal antibody to E-cadherine showing variable intensity of positive staining results which is compared with a protein-embedding bar code as designed in this chapter. Using computer-assisted image analysis with a special software, an automatic quantitative measurement of protein is performed. See color insert.

Collect sections on acetone-washed copper grids (see Subheading 2.2.) View directly or positive stain with uranyl acetate and lead citrate (sections can be stored in a grid box)... 

Table 5 Summary of Positive Stains Routinely Employed in TEM ...

Light and electron microscopic studies were performed on the synovial membranes (E2) of patients with HIV associated arthropathy. An immunoperoxidase technique with the use of monoclonal antibodies against CD4, CD8, B, and DR lymphocytes and HIV p 24 antigen was also used. Mild to moderate nonspecific proliferative changes and increased vascularity of the subsynovial space were seen. Immunohistochemical staining revealed HIV p 24 positive staining cells of the synovial lining layer and the mononuclear cells of the subsynovial space, CD4, CD8 with predominance of CD8, B, and DR cells were also present. 

Samples in tubes 2 and 3 (see table below) are single-stained standards that will be used for setting compensation. These should contain a substantial number of apoptotic and/or necrotic cells, so that subsets that are positively stained with annexin V-PE and/or 7-AAD may be readily recognized, and are best prepared from designated replicates of test samples that have been exposed to a high concentration of toxicant. 

When analyzing an immunostained specimen, deposits of the colored chromogen indicate the presence of the antigen and represent specific positive staining. The pattern of staining in the cells can be cytoplasmic, nuclear, membranous, or surface focal or diffuse. This section addresses some of the most common problems encountered in immunoperoxidase procedures and the appropriate solutions to correct them (see Chapters 23-25). (See Note 4 for additional troubleshooting resources.)... 

Of particular inferesf was the observed strong correlation obtained between STC2 mRNA levels and its cognate protein levels. Using tissue microarrays from 216 breasf tumor samples, in situ hybridization with a probe to STC2 mRNA was performed wifh 75 tumors and showed positive staining 83% of fhe mRNA-positive tumors identified for STC2 protein by... 

Be sure to remove the extraembryonic membrane. Failure to do this may result in the lower colorimetric detection due to the reduced penetration of the probe. If technically difficult, the extraembryonic membrane should be at least partially torn. Additionally, be sure to puncture the vesicular structures such as brain, heart, and otic vesicles to prevent the false-positive staining caused by trapping of the probe. 

However, connexins do not seem to be restricted to the transverse cell boundaries, since they have also been detected in several specimens at the lateral cell side. For example Oosthoek et al. [1993b] demonstrated Cx43-positive staining at the lateral cell side of human and bovine hearts (ventricles). Figure 10 shows another example from the rabbit heart, using an anti-Cx43 monoclonal antibody in cryostat sections of the rabbit left ventricle. Please note the distribution of Cx43 positivity at the transverse cell boundaries and at the lateral cell sides. 

Chen L, Goings GE, Upshaw-Earley J, Page E Cardiac gap junctions and gap junction-associated vesicles Ultrastructural comparison of in-situ negative staining with conventional positive staining. Circ Res 1989 64 501-514. 

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