Samples and shipping

What does the UK laboratory require?

The Edinburgh CSF laboratory asks for a minimum of 0.6 ml of clear and colourless CSF. Blood-stained CSF is not accepted because it invalidates the test, and samples with a red cell count above 1,250 are not accepted. Total protein above 1 g/L and a white cell count above 20 may interfere with the assay. The sample should be frozen within two to three hours of collection: a standard minus 20 degree freezer is acceptable and minus 70 or minus 80 degrees is preferred.

The CSF RT-QuIC request form must be completed and emailed before the sample is sent, to the named laboratory contacts, and a hard copy of the completed form must accompany the sample. The laboratory cannot process samples without it, and the form has to carry the responsible consultant’s and the referring laboratory’s email addresses so the report reaches the right place. The sending institution is responsible for transport arrangements and costs. Samples are accepted through Stores on weekdays between 9:00 and 15:30, and staff are asked to email the laboratory with an approximate arrival date and time after dispatch. Results are reported electronically only from July 2025.

Packaging and delivery address details sit on separate pages of the laboratory’s own site and should be taken from there, since neither the sample requirements page nor the transport page states them.

What does the US centre require?

Collect 2 ml of CSF by lumbar puncture, with a 1 ml minimum, discarding the first 2 ml that flows from the tap. The preferred tube is a Sarstedt polypropylene low-binding sterile tube, catalogue number 63.614.625. Freeze the sample immediately, at least in a minus 20 degree freezer, and ship frozen on dry ice. Samples are not received at weekends or on holidays, so shipment goes Monday to Thursday by priority overnight service. The CSF test requisition form is submitted with the order. Patients must be aged 12 or older, and the service assumes a history of a rapid neurodegenerative condition with no conditions that could compromise the result.

Bloody or insufficient samples are unacceptable, and the centre states that samples that are coloured or contain blood cannot be tested for RT-QuIC or 14-3-3 gamma. Shipping at room temperature reduced accuracy for all three assays compared with frozen shipment on dry ice. Turnaround is about five business days from receipt.

The centre also names discoloured CSF among the causes of a false negative RT-QuIC result, alongside atypical disease types, patient age and disease duration, which is a reason to repeat a borderline collection instead of accepting a poor sample.

What does the Australian registry require?

Clear, non-haemolysed CSF with a minimum volume of 1.5 ml, and the instruction not to spin the sample or process it further. The registry asks to be notified before samples are sent, and requires the original request slip and the CJD specimen data sheet, together with the routine microbiology and biochemistry results covering red and white cell counts and protein. Specimens are double bagged.

Samples can be refrigerated at 2 to 8 degrees and sent within two days, or frozen and sent on dry ice. The registry’s stability table gives under two days at room temperature, under four days at 4 degrees, and indefinite stability frozen, with freeze and thaw cycles not affecting the sample. CSF in other tube types, or already refrigerated or frozen, remains suitable for 14-3-3 and RT-QuIC. Samples that do not meet the collection criteria can still be tested, with results carrying caveats. Testing runs weekly on Mondays, with stated closures over public holidays, the Christmas and New Year period, Easter and the Melbourne Cup Carnival, during which samples are held at minus 20 or minus 80 degrees.

What about blood for genetic testing?

The Australian registry asks for at least 5 ml of EDTA blood, labelled for DNA extraction and storage or for PRNP testing, and recommends storing blood from every suspected CJD patient so that relatives can be tested later. Storage is optional and testing is voluntary. The registry recommends genetic counselling because of the medical, ethical, psychological and legal issues for relatives, and PRNP testing is performed at the Neurogenetics Unit of PathWest Laboratory Medicine WA in Nedlands.

Taking and storing blood during the acute illness avoids a situation where the only route to a genetic answer later is tissue obtained at post-mortem examination. Consent for storage and consent for testing are separate decisions, and the testing decision sits with the family and a genetic counselling service.

What are the handling and transport rules on the ward?

UK guidance classifies body secretions and fluids including saliva, blood, CSF and excreta as low risk for CJD, so samples from patients with or at increased risk are handled with standard infection prevention and control precautions as for any other patient: disposable gloves and eye protection where splashing may occur, avoidance of sharps injuries, safe disposal of sharps and contaminated waste under local arrangements, and single-use disposable equipment wherever practicable. Samples should be marked to indicate that a sample is being sent.

Different rules apply to medium and high risk tissue. When taking a biopsy of medium or high risk tissue, such as tonsil biopsy in suspected variant CJD, every effort should be taken to minimise the risk of infecting the operator or contaminating the environment, and only trained staff who are aware of the hazards should carry out such procedures. Where a brain biopsy is being considered, the guidance directs clinicians to its own annex on the management of instruments and tissues from brain biopsy procedures. The ACDP guidance set also includes a separate annex on the transport of TSE-infected material and an annex for pathology laboratories handling tissues from these patients, which is where the packaging and classification requirements for tissue consignments are set out.

Which laboratory the sample goes to is covered in testing labs by country, the referral and notification steps around it in suspected case pathway, and the section index is for clinicians.