Basics of Light Microscopic Analysis of Synovial Fluid

Light microscopy of synovial fluid is an established diagnostic technique widely used for the detection of fluid microstructures. Proficient use of the microscope will allow maximum information to be obtained from the sample. It is also important to handle the synovial sample with care. The initial microscope assessment of synovial fluid is that of examination of a ‘wet prep’ sample which consists of unstained, undiluted synovial fluid. It is best to assess the sample as soon as possible after collection as fluid material in particular crystals may degrade quickly. This is especially true for calcium pyrophosphate crystals which are very fragile. Further assessments on the sample can include gram staining for microorganisms and the identification of unusual cells that may further the clinical diagnosis which include fat droplets, large mononuclear cells, cartilaginous fragments, LE cells and sickle cells.