Alcian Blue - PAS Stain

This is a combined method utilizing the properties of both the PAS (see PAS) and Alcian blue (see Alcian blue) methods to demonstrate the full complement of tissue proteoglycans.
 
The rationale of the technique is that by first staining all the acidic mucins with Alcian blue, those remaining acidic mucins which are also PAS positive will be chemically blocked and will not react further during the technique.  Those neutral mucins which are solely PAS positive will subsequently be demonstrated in a contrasting manner.  Where mixtures occur, the resultant color will depend upon the dominant moiety.
 
The combined result from the port-manteaux method demonstrates both acidic- neutral- and mixtures of acidic and neutral mucins.


Result:
acidic mucins: blue
neutral mucins: magenta
mixtures of above: blue/purple
nuclei: deep blue