الفهرس 
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Abstract
microscopic control is again necessary, acid differ¬entiation is generally quicker, particularly if large numbers of slides are being stained at the same time.
In both types of differentiation stain is removed from all tissue components at more or less the same rate. Structures which bound more dye initially will retain more and remain coloured for longer. Differentiation is discontinued when only the structures of interest (usually nuclei) are still clearly visible. Over differentiation can be corrected by washing out the differentiator and returning the sections to the haematoxylin solution.
The use of acid as the differentiator also favours the reddish form of haematein, both soluble and bound. Although the dye complexes are stable in this form it has become standard practice to convert haematein to the blue complex, as this contrasts more effectively with various anionic counterstains. This process requires that sections be washed in a solution of pH>5.0.(31) In most cases ordinary tap water will suffice, but may take a few minutes. Virtually instantaneous conversion can be obtained with a weak ammonia solution or a dilute solution of lithium carbonate.