Automated methods and devices that facilitate iterative staining of biological samples from imaging applications are provided. The methods include the steps of providing a small volume flow cell containing a biological sample, applying a stain to the biological sample, combining at least two precursor reagents to form an activated destaining agent and wherein the activated destaining agent decomposition rate is greater than or similar to the destaining reaction rate, and flowing the destaining agent over the biological sample at a flow rate that is greater than the decomposition rate of the activated destaining agent. The process of staining, combining and flowing may be iteratively repeated. Also disclosed herein are devices for iterative staining of biological samples comprising a flow cell, in fluid communication with a premixer, wherein the volume capacity of the premixer is smaller than about five times the volume capacity of the flow cell.