ABC of Safety in the Biological Sciences
CEREBROSPINAL FLUID (CSF) (also see body fluids)
The cerebrospinal fluid (CSF) envelopes the brain and spinal cord acting as a buffer against mechanical shock (see also Body fluids). It is clear and watery and contains salts and organic compounds in solution. It is formed by the choroid plexus in the ventricles and possibly by ependymal cells and is in essence a dialysate of blood. CSF samples are obtained by lumbar or cisternal puncture.42
In normal conditions CSF is clear, acellular and sterile but can contain pathological organisms in disease states when it may appear cloudy, blood-stained or purulent. The specimen obtained must be handled with the care afforded any potentially infectious material (see body fluids).