Bright-field microscopy is the most fundamental and widely used form of transmitted-light optical microscopy. It is the standard microscopy method underlying routine examination of many stained microbiological specimens, blood smears, tissue sections, cytological preparations and histopathological specimens. Its defining feature is simple: The specimen is illuminated with transmitted white light, producing a bright background, while structures within the specimen appear darke

Principles, Types, Staining Methods, Clinical Applications & Troubleshooting Microscopy is one of the oldest—and still one of the most useful—tools in clinical microbiology. Before culture, antigen detection, PCR and sequencing became routine, microbiologists depended almost entirely on what could be seen under the microscope. Even today, microscopy can provide an answer within minutes: Are bacteria present? Are they Gram-positive or Gram-negative? Are yeast cells present? Ar