In histopathological techniques, what is the primary feature of regressive staining?

Regressive staining is characterized primarily by the step of decolorization, which is essential in the process. This technique starts with the tissue being stained with a dye that binds to all the components of the cells or tissue. Following this initial staining, a decolorization step occurs to remove excess dye from areas where it is not retained, allowing for a clearer, more defined contrast of the specific cellular structures that remain stained. This process is crucial because it highlights the target structures while eliminating background staining, resulting in improved visibility of the histological features under the microscope.

The other options do not accurately reflect the main attribute of regressive staining. While tissue resolution can certainly be enhanced as a result of the staining process, this is not uniquely tied to regressive methods as it can be a feature of various staining techniques. Specific staining of cell membranes is not a defining feature of regressive staining; rather, it is a characteristic that may pertain to specific stains designed for membrane components. Lastly, the notion that regressive staining is used exclusively for carbohydrates is incorrect; this method can be applied to a wide array of tissue components, not limited to carbohydrates alone.