Histotechnology I- Miscellaneous
Question No. 20. The Answer is: (E) Give a darker staining intensity with longer staining time.
Discussion: The first four answers are obviously jokes. I hope they would serve as the spices of your day. In general, hematoxylin stains are divided into the so-called progressive formulae and regressive formulae. The progressive formulae stain far slower then that of the regressive formulae and therefore the staining intensity can be controlled by the length of the staining time. Hematoxylin stains with regressive formulae involve over staining the sections followed by a differentiation step to achieve the desired staining intensity. The regressive formulae are particularly useful for tissues that do not take up hematoxylin well. One of the best examples is over decalcified tissue.