А METHOD FOR THE DIFFERENTIAL STAINING OF 
FUNGOUS AND HOST CELLS 
R. E. VAUGHAN 
Assistant in Plant Pathology, University of Wisconsin 
Exchange Fellow in the Henry Shaw School of Botany of Washington University 
In making histological studies of fungi on living or dead 
plant tissues the use of the stain known as “Pianeze IIIb” 
has been found very satisfactory in differentiating the fungus 
from the plant substratum, this differentiation occurring both 
in lignified and unlignified cell walls. Тһе host tissue stains 
green and the mycelium a deep pink. This stain, devised 
by Dr. Pianeze for the study of cancer tissue,! is made up as 
follows: 
Malachite адтгееп.......................... 0.50 gm. 
nr С 0.10 gm. 
CORPOS | gn ar 0.01 gm. 
Water, distilled........... BS es .. .. 150.00 ce. 
Alcohol, 95 pet се. Е. ........... .. 50.00 се. 
Dr. Pianeze reports that it gives the following staining 
reactions: green in chromatin of resting or dividing nucleus, 
rose in cell protoplasm and membrane, and red in cancer bodies. 
For use with plant tissues the procedure is as follows: Wash 
in water or alcohol, stain in the undiluted mixture 15-45 
minutes, remove excess stain in water, and decolorize in 95 
per cent alcohol to which a few drops of hydrochloric acid have 
been added. For permanent mounts, clear with a carbol- 
turpentine mixture, remove clearer in xylol, and mount in 
balsam. Preparations of Stereum, Corticium, and Polystictus 
have been made with great success. 
This stain is also valuable for staining germinated spores on 
the surface of a leaf. The procedure in this case is as follows: 
Infect marked portions of a leaf with a suspension of spores 
applied with a pipette, and place the plant under suitable 
conditions for fungous growth for 24-48 hours. Then permit 
1Pianeze, G. Beitrag zur Histologie und Aetiologie des Carcinoms. Beiträge 
2. path. Anat. и. z. allg. Path. Supplement т: 1-193. 1896. [ef. p. 58.) 
ANN. Mo. Вот. GARD., Vor. 1, 1914 (241) 
