Ribonucleic acid content of Burkitt tumour cells.

Methyl-green-pyronin-Y staining was performed on 57 biopsies of Burkitt's tumour and 62 biopsies from other types of malignant lymphoma. The specificity of the pyronin staining for ribonucleic acid (RNA) was controlled by staining duplicate slides previously digested in ribonuclease. Burkitt's tumour cells have a higher cytoplasmic content of RNA than the cells of most other malignant lymphomas. The results of acridine orange staining of a smaller number of biopsies support these findings.