1. Use CSF Collection Kit (available from stores)
2. Disinfect site with 2% iodine tincture or 70% alcohol.
3. Insert a CSF needle with stylet at L3-L4, L4-L5, or L5-S1 interspace.
4. On reaching the subarachnoid space, remove the stylet and collect 2-5 mL of fluid in each of three leak proof CSF tubes.
5. Use Sterile pack of 3 screw-cap CSF tubes.
6. The Lab will use:
   Tube 1 for Biochemistry
   Tube 2 for PCR
   Tube 3 Cell for count/culture
7. Minimum CSF volumes:
   Average Volume 2-5 mL
   Culture = 1.0 mL
   Chemistry = 0.5 mL
   PCR = 0.5 mL
   Fungi = 2.0 mL
   AFB = 2.0 mL
   Oligoclonal Bands = 1.0 mL

IT IS PREFERABLE THAT THE SPECIMENS ARE HAND DELIVERED TO THE LABORATORY AND NOT SENT VIA THE PNEUMATIC TUBE SYSTEM.

1. Antigen testing on CSF is no longer recommended because of poor Sensitivity/Specificity (Latex 52%/97% Gram Stain 70%/96%)
2. If PCR is requested Tube 2 is sealed to prevent contamination and sent for PCR testing. PCR testing in the presence of a normal CSF leucocyte count is not routinely performed by the reference laboratory. This is based on an analysis of previous PCR results and CSF Cell Counts.
3. Concomitant blood cultures may be collected.
4. CSF may be sterile in cases of Brain Abscess or Encephalitis.
5. Microscopy results routinely available within the hour.
6. Interpretation of the Cell count

Polymorphonuclear Cells
Bacterial infections (eg, meningitis, cerebral abscess, early tuberculous meningitis, septicaemia) are usually associated with the presence of neutrophils in the CSF.

Mononuclear Cells
Viral infections (eg, 'aseptic meningitis', encephalitis) are associated with an increase in mononuclear cells, although in some (eg, Coxsackievirus, poliovirus infection) there may be an early increase in neutrophils. An increase in mononuclear cells may also be seen with cerebral abscess, acute leukaemia, lymphoma, intracranial vein thrombosis, cerebral tumour or multiple sclerosis. An increase in both neutrophils and mononuclear cells occurs in cerebral abscess, tuberculous meningitis and early viral meningitis.

Eosinophils
Eosinophils are seen in meningitis caused by Angiostrongylus cantonensis and in cysticercosis and coccidioidomycosis.

Erythrocytes
Red cells are present after subarachnoid haemorrhage and trauma and with haemorrhagic inflammation (eg, HSV encephalitis).