1.3.2
Step 2: Obtain a Sample
Sample Types
Whole blood samples: Use only lithium heparin test tubes (green top).
Plasma samples: Obtain these from whole blood samples (lithium heparin).
Serum: Obtain from a sample placed in a red top test tube.
Note:
Do not use EDTA (lavender top test tube) for any samples to be tested on the VetScan
VS2 Chemistry Analyzer.
Guidelines for Obtaining Samples
Serum samples: Use no-additive evacuated specimen collection tubes or serum separa-
tor tubes.
Whole blood or plasma samples: Use only lithium heparin evacuated specimen collec-
tion tubes.
Obtain a sample of approximately 100 µL.
When collecting the sample in lithium heparin collection tubes, fill the tube at least half-
way to maintain the proper ratio of sample to anticoagulant.
Run samples within 60 minutes. If this not possible, spin down and remove the plasma or
serum.
Place the plasma or serum into a clean red top tube, and run within five hours. If this is
not possible, refrigerate the sample in a stoppered container at 2–8 ºC (36–46 ºF) for no
longer than 48 hours. A plasma or serum sample can also be stored at -10 ºC (14 ºF) for
up to five weeks in a freezer that does not have a self-defrost cycle.
Guidelines for Handling Samples
Use the following guidelines and procedures to ensure best results.
Before dispensing, remove the needle to avoid hemolysis.
Dispense the sample slowly into the sample tube.
For dehydrated patients: Use plasma, or allow the sample to settle for 5 minutes and
then draw from the top of the sample.
Quick Reference Guide
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