
My own saliva stained with methylene blue. Personal buccal epithelial cells are visible as large pale blue cells with a dark staining nucleus. Numerous bacteria are visible either attached to the cells or in other parts of the stained sample. 1000x

My own saliva stained with methylene blue. Personal buccal epithelial cells are visible as large pale blue cells with a dark staining nucleus. Numerous bacteria are visible either attached to the cells or in other parts of the stained sample. 1000x

My own saliva stained with methylene blue. This is cluster of cocci shaped bacteria from my mouth . 1000x

My own saliva stained with methylene blue. Personal buccal epithelial cells are visible as large pale blue cells with a dark staining nucleus. Numerous bacteria are visible either attached to the cells or in other parts of the stained sample. 1000x

My own saliva stained with methylene blue. Personal buccal epithelial cells are visible as large pale blue cells with a dark staining nucleus. Numerous bacteria are visible either attached to the cells or in other parts of the stained sample. 1000x

My own saliva stained with methylene blue. Personal buccal epithelial cells are visible as large pale blue cells with a dark staining nucleus. Numerous bacteria are visible either attached to the cells or in other parts of the stained sample. 1000x
Paul Ehrlich’ made countless contributions to science, in fields as diverse as histology, haematology, immunology, oncology, microbiology and pharmacology. His discovery of arsphenamine (Salvarsan) for the treatment of syphilis, and which was the first modern antibiotic, won him wide international acclaim. His early contributions in the field of antibiotic therapy were decisive in initiating the wider development of antibiotics decades later.
In the course of his investigations Ehrlich came across methylene blue, which he regarded as particularly suitable dye for staining bacteria (later, Robert Koch also used methylene blue as a dye in his research on the tuberculosis pathogen). In particular in stained preparations, Ehrlich noted that bacteria, and the nucleus of human cells which contains the cell’s DNA, both stained blue, but not other parts of the human cell.
Here I have drawn upon Ehrlich’s early studies on staining bacteria and developed a simple off-the shelf/ DIYBio-staining procedure for bacteria, yeast and human cells. It is based on methylene blue which is readily available as a “fish medicine”. The brand I used here is King British Methylene Blue. It works very well as it comes in the bottle, and without the need for any messy preparation.