Quantitative immunohistochemistry evaluation

It may be helpful to consider the following criteria when evaluating a proposed positive control for immunohistochemistry. A positive control is ideally (1) reproducible and quantitative, (2) available in unlimited quantities, (3) antigen-specific, (4) inexpensive, and thereby adaptable for mass production, and (5) stable over time. Judged against these criteria, current practice falls short of the ideal. Biopsy materials are variable, both from patient to patient and even within a single tumor sample. Biopsy or resection materials are also obviously not available in unlimited quantities. The need for (microtome) sectioning of each positive control also creates a labor cost that is often under-appreciated by many clinical IHC laboratories. 

Note that although immunohistochemistry is contributing significantly to clinical information, in the absence of quantitation, this method is subjective and prone to intra- and interobserver variations. To assure the reproducibility of histopathological results and then-correct evaluation, at least an assessment of the percentage of positive cells and both the staining pattern and intensity must be made. If available, computer-assisted image analysis... 

Seven-week-old Wistar rats at normal iodine basehne were divided into four different groups and fed on water of normal, 1.5-fold, 3-fold and 6-fold iodine levels for 8 months. Transmission electron microscope, flow cytometry, DNA quantitation and annexin V early apoptosis detection technique were combined to evaluate intracellular ROS level expression of apoptosis-related molecules (Fas, FasL, bcl-2, bax) was traced by indirect fluorescent stained flow cytometry and immunohistochemistry qualitative and quantitative analyses of cell apoptosis were performed by terminal deoxynucleotidyl transferase mediated dUTP nick end labeling (TUNEL) staining. 

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