Avoiding hemolysis in serum specimens
Conduct a ‘clean’ phlebotomy by:
– Avoiding bruised areas
– Drying the skin after cleanser use
– Stabilizing the target vein to minimize needle tip movement
– Using a straight needle whenever possible, instead of needles with long lines or connections (unless indicated in your protocol)
– Using a discard tube if the draw is complicated or when drawing through a line or device
– Avoiding the use of a syringe to aspirate
Process the whole blood specimen as instructed when preparing serum for Covance CLS analysis!
– Mix it as instructed, not too much
– Don’t let it roll around or lie flat
– Let it sit undisturbed and vertically in a rack for 30 to 60 minutes for the clot to form and to start gel migration
– Handle it gently and keep it vertical between the rack and the centrifuge to avoid re-mixing cells into serum
Maintain your centrifuge! – Check that it has been maintained properly and is performing well and safely
– Understand the special relationship on your own centrifuge between its rotating radius, speed (the RPM or revolutions per minute) and g-force, details are in your Investigator Manual
– Make your centrifuge settings produce the needed g-force, not too much, not too little: target 1500 to 2000 g (or as instructed on the laboratory requisition), and run this for the right amount of time, 15 minutes (or as instructed on the laboratory requisition).
Too much g-force: ruptures Red Blood Cells causing hemolysis
Too little g-force: traps more Red Blood Cells above the gel, where they can be aspirated into the pipette – Transfer the primary collection tube gently into a rack, to avoid re-suspending Red Blood Cells into the serum
– Have the primary collection tube in a rack while pipetting, to ease this task
– Sit down to pipette, to ease this task
– Use both hands to steady the pipette
– DO NOT UNDER ANY CIRCUMSTANCES TOUCH THE SURFACE OF THE GEL WITH THE PIPETTE TIP, this guarantees aspirating Red Blood Cells into the pipette and serum
– AVOID THE SURFACE OF THE GEL, that’s where some of the Red Blood Cells are…they just never made it into the gel
The GOAL: Avoid getting Red Blood Cells in the serum specimen and reduce the risk of cancellations due to hemolysis.