Hematology: Sample Collection and Handling Flashcards
Sample collection
Need to know which tests are being run before you start so you know how much blood you need
What two pieces of equipment are needed to draw blood?
Needle and Syringe
What happens if the needle is too small?
Can cause hemolysis
What happens if the syringe is too large?
Can collapse the vein
What happens if the syringe is too small?
May not get enough blood with one puncture and have to repeat
What is the preferred method of blood collection?
Vacutainer because you can get multiple samples with one stick
What does using a vacutainer ensure?
That the anticoagulant is in the proper ratio to blood
What tubes do you need if you need serum
Red top tube (RTT)
Serum seperater tube (SST)
What tubes do you need if you need plasma?
Green top tube (GTT)
Blue top tube (BTT)
What tubes do you need if you need whole blood?
Lavender top tube (LTT)
Plasma
Fluid portion of whole blood (unclotted)
Contains fibrinogen
GTT/BTT
90% water, 10% dissolved constituents
Serum
Fluid portion of clotted blood
Does not contain fibrinogen
RTT/SST
What does RTT and SST not contain
Anticoagulant
What happens during clotting
20 mins
Fibrinogen is converted to insoluble fibrin clot matrix
The clot squeezes out the serum in the centrifuge
What has a different protein concentration than serum?
Plasma
What do anticoagulants bind?
Calcium
When are anticoagulants required?
When whole blood or plasma is needed
Can serum or plasma be frozen?
Yes if it is placed into a new tube without the red blood cells
What are the abnormal colors of serum?
Icteric
Hemolytic
Lipemic
Heparin
Green Top Tube (GTT)
Lithium and sodium heparin
What are the benefits to heparin tubes?
Do not need to wait for the tube to clot
What are heparin tubes used to obtain
Plasma for clinical chemistries
Citrates
Blue top tube (BTT)
Sodium citrate or lithium citrate
What does sodium citrate interfere with?
Sodium assays
What does sodium citrate prevent?
Clotting by binding with calcium
What tests use citrated plasma?
Coagulation tests
Blood transfusions
Gray top tubes
accurate glucose testing
Not commonly used
What is the rule of thumb?
Get enough to run the test 3 times
Well-hydrated animal
(PCV 50%)
50% cells, 50% fluids
10ml blood=5ml fluid
Dehydrated animals
PCV 70%
70% cells, 30% fluids
10ml blood=3ml fluid
EDTA
Ethylenediamineteraacetic acid
Lavender Top Tube
EDTA
Chelates (bonding of) calcium
What does LTT not alter?
Cell morphology
What tests are LTT tubes good for and what are they not good for
Complete Blood Counts
Chemical Assays
What do excessive amounts in LTT cause?
Excessive amounts cause cells to shrink and invalidates cell counts in automatic analyzers
What does poking the needle through the top of the tube cause?
Hemolysis
What order should the tubes be filled in
Citrate Plain red Tiger top/serum separator Green/heparin Lavender Gray
