The composition of CSF is based on selective secretions from the plasma. CSF has higher concentrations of some solutes and lower concentrations of other solutes. For example, the protein level of normal CSF is dramatically lower than that of plasma. Chemical substances that are often evaluated in CSF samples are listed in Table 1.
Table 1. Chemical Substances in CSF and Reference Intervals.| Chemical | CSF Reference Interval |
| Chloride | 120–132 mmol/L |
| Total Protein | 15–45 mg/dL |
| Glucose | 40–70 mg/dL |
Other chemicals that are also present in CSF include:
- Albumin
- Calcium
- Cholesterol
- Creatinine
- Immunoglobulins
- Lactic acid dehydrogenase (LDH)
- Magnesium
- Potassium
- Phosphorus
- Urea
- Uric acid
