Test Process

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The Karius Test

Test Process

The Karius Test

Karius Test Process

Karius Test reports are typically available 1 day after specimen receipt*

The Karius laboratory is CLIA-certified and CAP-accredited to perform high-complexity clinical laboratory testing.

* >85% of specimens received by 8:30 AM (PT) Monday through Saturday are reported the next day.

Step 1

Specimen Collection

5-mL standard blood draw in plasma preparation tube

Step 2

Specimen Processing

DNA extraction and library preparation

Step 3

Sequencing

Microbial cell–free DNA sequencing

Step 4

Analysis

Curated clinical-grade pathogen database

Consultations are available with Karius infectious disease physicians and clinical microbiologists.

Order the Karius Test

Specimen Collection & Preparation Instructions

PREFERRED METHOD
In Plasma Preparation Tube (PPT)

  1. Collect blood in PPT
    • 5 mL of whole blood in BD Vacutainer® PPT
    • Gently invert the tube 8-10 times after draw
    • Label the tube with the patient’s first and last name, a unique patient identifier (DOB or MRN), and the date and time of specimen collection
  2. Centrifuge within 6 hours of draw
    • 1100 RCF (g)?-?| 10 mins | Ambient temperature
    • Do not transfer plasma
    • If the specimen is unlikely to reach Karius within 96 hours of collection, freeze specimen directly in PPT after centrifugation
    • If the gel plug does not rise to separate the cells from the plasma, the tube should be re-centrifuged at a higher speed
  3. Submit a test requisition form
  4. Package specimen
    • Package the specimen and the completed requisition form using the supplies in the Karius Test kit
    • See shipping instructions below

ALTERNATIVE METHOD
In Lavender Top, K2-EDTA Tube

  1. Collect blood in K2-EDTA tube
    • Do not pool blood draws
    • Gently invert the tube 8-10 times after draw
  2. Centrifuge within 24 hours of draw
    • 1600 RCF (g)?-?| 10 mins | Ambient temperature
    • For tubes less than 4 mL, refer to the tube manufacturer’s instructions for centrifugation speed and time
  3. Transfer plasma
    • Transfer a minimum of 0.7 mL?_?of plasma into a sterile polypropylene tube
    • Do not disturb the buffy coat when transferring
    • Label the tube with the patient’s first and last name, a unique patient identifier (DOB or MRN), and the date and time of specimen collection
  4. See steps 3 & 4 of PREFERRED METHOD (above)

Specimen Stability
(After plasma has been separated from cells)

  • Stored at ambient temperature: 96 hours
  • Stored at -20˚C: 6 months

Rejection Criteria

  • Plasma separated from whole blood more than 6 hours (PPT) or more than 24 hours (K2-EDTA) after draw
  • Unfrozen specimen received at Karius more than 96 hours after draw
  • Specimen with incomplete or improper separations of plasma
  • Specimen collected in an expired tube
  • Specimen with fewer than 2 patient identifiers on the tube

Shipping Instructions

Ambient Temperature

(Specimen MUST arrive at Karius within 96 hours of draw)

All supplies needed for shipping at ambient temperature are included in the Karius Test kit.

  1. Place the specimen in the biohazard bag with an absorbent pad.
  2. Wrap the ambient gel pack around the specimen bag.
  3. Place the wrapped specimen bag in the foil bubble mailer and then in the Karius Test kit cardboard box.
  4. Add the printed Karius Test Requisition Form to the Karius kit cardboard box.
  5. Place the box in a FedEx® UN 3373 Category B Pak. The FedEx® Pak with a preprinted return label is included in the Karius Test kit.

Frozen

(For specimens stored at -20˚C after plasma has been separated from cells)

  1. Place the frozen specimen in a biohazard bag with an absorbent pad.
  2. Place the specimen bag on dry ice in an appropriate container, ensuring there is enough dry ice to prevent thawing during transport.
  3. Ship via FedEx First Overnight® to Karius.

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