A Rapid Method for Macerating Phloem

Sieve cells and sieve tube members can be macerated from the phloem of various organs of woody and herbaceous species by autoclaving the tissue in a mild macerating medium. This treatment does not digest the primary walls or the callose deposits on the sieve areas and sieve plates of the sieve elements. These cells can then be recognized by the fluorescence of their callose after staining with aniline blue. Sometimes adjacent sieve elements fail to separate and one can observe details of their junctures.