Sensa Core ST-200 aQua, Operator'S Manual

Page: 67 / 92

ST-200 aQua
Operator’s Manual
66
HANDLING AND COLLECTION
4. Sample Handling and Collection
Warning
: Human body fluid specimens may be contaminated with HIV or
other pathogens. Treat all specimens and collection devices and tools as
biohazardous materials.
A. Whole Blood
Whole blood specimens should be drawn carefully to avoid hemolysis.
Elevated potassium values may indicate a hemolyzed specimen; if
hemolysis is suspected, a new sample should be drawn and analyzed.
Finger stick methods should be avoided since they can result in elevated
potassium values.
1. Collect the specimen by venipuncture into a Lithium-Heparin or
Sodium-Heparin (green-topped) evacuated blood collection tube. For
Lithium analysis, a sodium-Heparin (green-topped) tube must be
used. Do not use ammonium heparin, EDTA or NaF tubes. Note the
time of collection.
2. Mix the specimen by gently inverting and rotating the tube. Do not
shake.
3. Analyze specimens within one hour of collection; beyond this time
falsely elevated potassium levels may be obtained.
4. For analysis on Na/K/iCa/Cl/Li/pH analyzer, specimens should be
measured within 3-5 minutes.
B. Serum
1. Collect the specimen by venipuncture into an untreated (red-topped)
tube. Fill the tube to at least 2/3 of the total volume. Note the time
of collection.
2. Let blood stand for 20-30 minutes to allow clot formation.
3. Rim the clot with an applicator stick, then centrifuge the tube for
10-15 minutes and transfer the serum to a clean specimen tube.
4. Serum may be analyzed immediately or stored at 4ºC for 24 hours or
frozen at -20ºC for up to one week. Sample must be brought to room
temperature and mixed well before assaying.