Serum vs. Plasma
What is the main difference between serum and plasma?
Serum is the liquid that remains after blood has clotted, while plasma is the cell-free part of blood when clotting is prevented by an anticoagulant.
What is the purpose of additives in blood collection tubes?
Additives preserve the blood sample for specific tests and prevent clotting.
What is the proper way to mix the blood and additive in a tube?
The tube should be gently inverted 8 to 10 times.
What type of tubes are used for blood cultures?
SPS tubes or special blood culture bottles.
Which component remains after blood clots?
Serum
Name a common anticoagulant used in lavender-top tubes.
EDTA
How many times should tubes be inverted?
8 to 10 times
What is the role of SPS in blood culture tubes?
SPS prevents blood clotting and supports bacterial growth for diagnosis.
Which contains clotting factors: serum or plasma?
Plasma contains clotting factors
Which additive is found in light blue-top tubes?
Sodium Citrate
What can happen if a tube is shaken vigorously?
Hemolysis may occur, leading to inaccurate test results.
Why are blood cultures important?
They are used to detect infections in the blood.
Describe the role of fibrinogen in serum.
Fibrinogen is a clotting factor that is absent in serum since it is consumed during the clotting process.
What is the function of heparin in green-top tubes?
Heparin prevents clotting and provides rapid results for STAT chemistry tests.
What is the blood-to-additive ratio?
the specific ratio varies by type of test and tube, and must be followed for proper testing
How do blood culture bottles support bacterial growth?
they contain additives that prevent clotting and provide an environment for bacteria to grow.
Why is it important to distinguish between serum and plasma in testing?
Different tests require serum or plasma based on the presence or absence of clotting factors, affecting test accuracy.
Why should tubes with additives be inverted instead of shaken?
Inverting prevents hemolysis and ensures proper mixing without damaging blood cells.
Why is proper tube handling essential for accurate test results?
Proper handling ensures that the sample is preserved correctly, avoiding contamination and ensuring valid test outcomes.
What is a common mistake when collecting blood cultures?
Not using aseptic technique, which can lead to contamination of the sample.