From the Research
EDTA tubes are recommended for cerebrospinal fluid (CSF) cell count analysis rather than heparin tubes. This recommendation is based on the fact that EDTA preserves cellular morphology better and prevents cell clumping, which is crucial for accurate cell counting and differentiation in CSF samples 1. Heparin tubes can cause platelet aggregation and may interfere with cellular staining techniques, potentially leading to inaccurate results. Additionally, EDTA tubes help maintain cellular integrity for longer periods if there is a delay in processing the sample.
When collecting CSF for cell count analysis, the sample should be transported to the laboratory promptly and analyzed within one hour of collection when possible to prevent cellular degradation. If multiple CSF tests are ordered, the tube for cell count should be collected first or second (after the tube for microbiological studies) to minimize the risk of traumatic tap affecting the cell count results. The use of EDTA for CSF cell count analysis is supported by its ability to chelate calcium and prevent blood clotting, allowing for more accurate cell counts and differentiation 2.
Some studies have compared the use of EDTA and plain tubes for CSF collection, but the most recent and highest quality study found no significant difference in the results of standard CSF analysis between the two types of tubes 1. However, EDTA tubes are still preferred due to their ability to preserve cellular morphology and prevent cell clumping.
In terms of the specific characteristics of EDTA tubes, they have been shown to be effective in preserving blood cells and preventing clotting, making them suitable for a variety of laboratory tests, including CSF cell count analysis 3, 4, 5. Overall, the use of EDTA tubes for CSF cell count analysis is recommended due to their ability to preserve cellular morphology and prevent cell clumping, which is crucial for accurate cell counting and differentiation.