The sterile tubes used for CSF collection are generally pre-numbered 1 through 3 or 4, with tube 1 being the first tube filled.
- If possible, tube 1 should be reserved for non-routine studies.
- Tube 2 can be used for immunology and chemistry testing.
- Tube 3 can be used for microbiology testing.
- Hematology analysis is typically performed on the last tube collected (3 or 4) to ensure that any peripheral blood that may have contaminated the sample during the lumbar puncture has cleared.
Whether 3 or 4 tubes are collected, the first tube obtained should not be used for microbiology or hematology testing because of possible contamination from the lumbar puncture.
