Staining internal control

Figure 1.2 Examples of immunostaining intensity from comparison of pRB-IHC in 27 cases of FFPE tissues of bladder cancer (Table 1.4). (A-D) Negative (<10%) showing a few weak positive nuclei (arrows) (E-H) moderate positive (>10%) (I-P) strong positive (>50%). Arrows indicate positive nuclear staining for some lymphocytes or other stromal cells as an internal control. Note the lack of nuclear hematoxylin counterstaining due to low pH AR treatment. The order of cases are indicated in Table 1.4. Reproduced with permission from Shi et al.. Biotech. Histochem. 2007 82 301-309. See color insert.

Leong3 postulated that internal controls were required to optimize the variable influences resulting from aspects of tissue preparation and factors intrinsic to the staining method. Various controls have been employed, includ-... 

In the confocal microscopy experiment, it is recommended to include a negative control. This could be done by incubating cells with phages at 4°C, which should minimize internalization and thus only result in cell surface localization. In addition, endocytosis inhibitors could be used to monitor this event. The subcellular localization could be assessed by co-staining with antibodies that are reactive with different intracellular compartments. For instance, early endosome can be visualized by an EEA1 antibody, whereas late endosomes can be stained by an antibody against the mannose-6-phosphate receptor. 

Figure 9.3 Inhibition of intimal hyperplasia by resveratrol in rabbits subjected to endothelial injury by denudation. Groups of eight New Zealand white rabbits, weighting 2.2 to 3.6 kg, were assigned randomly to control (untreated) (M), low (2 mg/kg/d) (L), and high dose (4 mg/kg/d) (H) resveratrol treatment, which was administered intragastrically for 5 weeks beginning 1 week before surgery. A 2-cm segment of injured iliac artery was excised, fixed in 4% paraformalin, embedded in paraffin, and sectioned at5-mm intervals from the proximal to the distal end. Representative sections were stained with hematoxylin/eosin. The external and internal elastic lamina were manually identified. Intimal proliferation index (IPI) was defined as the ratio of intimal area to [intimal+medial] area relative luminal area (RLA) was defined as the ratio of luminal area to [luminal+intimal+medial] area.

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