NEISSER solution I (methylene blue) is an aqueous, methylene blue solution which is acidified with a little acetic acid and is used in microbiology and bacteriology for the staining of bacterial cells.

The special suitability of this solution lies in the examination of gram-negative diplococci, especially in the identification of Neisseria gonorrhoeae and Neisseria meningitidis. The staining allows improved visibility of cell structures and facilitates differentiation of the various bacterial species.

Chemically, the operation of the solution is based on the interaction of methylene blue and acetic acid. Methylene blue, a basic dye, binds to the acidic components of bacterial cells, particularly nucleic acids. Acetic acid serves as a fixative that stabilizes cell structures and enhances dye binding to cells.

The advantages of NEISSER Solution I (Methylene Blue) are its specific applicability to Gram-negative diplococci and the clear visualization of these bacterial structures. The solution enables rapid and efficient identification of Neisseria species, which can be crucial in the diagnosis of infectious diseases.