ACIDULATED PHLOROGLUCINOL
SPECIFIC FOR DIAGNOSTIC COLOR STAINING PROCEDURE STAINING TIME
PREPARATION
Lignin Red Place sections in drop of reagent solution on slide and cover with coverslip. Saturated solution of Phloroglucinol in 18% HCl

COVER REAGENT BOTTLE WITH ALUMINUM FOIL TO INHIBIT PHOTODEGRADATION
Lignin Fluoresces Light Blue in Unstained Condition 
(See Second  Image Below)
NB. Phloroglucinol Staining Eliminates Fluorescence
IMPORTANT NOTES:
  1. SECTIONS SHOULD BE MOUNTED ON SLIDES AWAY FROM MICROSCOPE TO PROTECT THE MICROSCOPE!!!
  2. GREAT CARE SHOULD BE EXERCISED TO AVOID CONTACT OF ACID WITH MICROSCOPE!!!
  3. Stain degrades in light and therefore is not permanent