A method of staining microorganisms using a violet stain. In this test, a sputum specimen is examined under the microscope.
Sputum is the mucous secretions produced by the lower respiratory tract.
The gram stain method can be applied to almost any clinical specimen and is one of the best techniques for the rapid diagnosis of bacterial infections. The specimen is stained with a violet stain known as a gram stain and then examined under the microscope for the presence of bacteria. The color, number, and morphologic appearance of the cells make it possible to identify the genus of the organism. If coughing does not produce sputum, a breathing treatment may precede the test to induce sputum production. Occasionally, the sputum is collected by bronchoscopy , and more discomfort is associated with this procedure.