Table 2.
Guidelines for procedure of CSF withdrawal.
| Item no. | Procedure | Ideal situation |
|---|---|---|
| (A) Collection procedures | ||
| (1) | Preferred volume | At least 12 mL. First 1-2 mL for basic CSF assessment (item 26). Last 10 mL for biobanking. Record volume taken and fraction used for biobanking, if applicable. |
| (2) | Location | Vertebral body L3–L5 |
| (3) | If bloody | Do not process further. |
| Criteria for bloody: more than 500 red blood cells/μL. | ||
| Record number of blood cells in diagnostic samples. | ||
| (4) | Type of needle | Atraumatic |
| (5) | Type of collection tube | Polypropylene tubes, screw cap, volume >10 mL. |
| (6) | Time of day of withdrawal and storage | Preferably standardized within each center allowing for intercenter differences in local logistics. |
| Record date and time of collection. | ||
| (7) | Other body fluids that should be collected simultaneously | Serum |
| (8) | Other body fluids that should be collected simultaneously | Plasma: EDTA (preferred over citrate). |
|
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| (B) Processing for storage | ||
| (9) | Storage temperature until freezing | Room temperature before, during, and after spinning. |
| (10) | Spinning conditions | Serum: 2,000 g, 10 min at room temperature. |
| CSF: 400 g, 10 min at room temperature/2,000 g if no cells are to be preserved. | ||
| (11) | Time delay between withdrawal and spinning and freezing | Optimal for CSF: 1-2 hours |
| Optimal for serum: 30–60 min. | ||
| Thus doing “both body fluids simultaneously”: ideally within one hour. | ||
| After spinning, samples must be aliquoted and frozen immediately for storage at −80ºC. | ||
| (12) | Type of tube for aliquoting | Small polypropylene tubes (1 to 2 mL) with screw caps. Record manufacturer. |
| (13) | Aliquoting | A minimum of two aliquots is recommended. The advised research sample volume of 10 mL should be enough for >10 aliquots. |
| (14) | Volume of aliquots | Minimum 0.1 mL. Depending on total volume of tube: 0.2, 0.5, and 1 mL. Preferably, the tubes are filled up to 75%. |
| (15) | Coding | Unique codes. Freezing-proof labels. Ideally barcodes to facilitate searching, to aid in blinding the analysis and to protect the privacy of patients. |
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| (C) Storage conditions and administration | ||
| (16) | Freezing temperature | −80ºC |
| (17) | Additional items on sample collection protocols that must be recorded | Location of samples |
| (18) | Additional items on sample collection protocols that must be recorded | Surveillance of freezers |
| (19) | Additional items on sample collection protocols that must be recorded | Splitting of samples over two or more freezers |
| (20) | Transport conditions | Always on dry-ice, sufficient volume of dry-ice for minimal 3 days of transport. |
| Initiated on Mondays. | ||
| Avoid high temperatures for thawing and mix thoroughly. | ||