ABSTRACT
The plant tissues, mainly the cell walls, are destroyed in two stages at room temperature and in a liquid medium. The first step is the hydrolysis of polysaccharides by sulphuric acid and the second is the oxidation of lignin by sodium hypochlorite. At the end of these two treatments, only the elastomer remains The neutralized samples are gently and separately arranged in Petri dishes containing water. The principal morphological characteristics still preserved in the lignin are recorded according to the descriptive profile. The oxidizing solution of sodium hypochlorite 2M is added drop by drop on the samples. A final test of coloration with a safranine solution, which is not fixed by the elastomer, can be used to detect the presence of residues of cell walls and to eliminate them by prolonging the hypochlorite treatment.
