Methods: RBC/WBC Indices Flashcards
Manual Techniques:
-MCV equation
MCV = Hct x (10/RBC count)
*Hct expressed as %
Manual Techniques:
-MCHC equation
MCHC = (Hgb/Hct) x 100
*Hct (%); Hgb (g/dL)
Automated Techniques - Hemoglobin:
- Method
- How/What is it measured
- Absorbance
- Do NOT detect what Hb form?
Cyanohemoglobin/Hemiglobin Cyanide (HiCN) method
- [HiCN] measured by spectrophotometry
- 540 nm
- Sulfhemoglobin (SHb)
Automated Techniques - Cell Counts:
-What sized particles are counted as RBCs
36-360 fL
Automated Techniques - Cell Counts:
-Following lysis of RBC; what size particles are counted as WBCs/Platelets?
- WBC >36 fL
- Platelets <36 fL
What RBC indices relflects anisocytosis?
RDW
What may cause a high MCHC? (3)
- Spherocytosis
- Cold Agglutinin
- Lipemic specimens
What are two rapid tests to detect hemoglobin S?
- Dithionate/Hemoglobin Solubility Test
- Metabisulfite/Sickling Test
What does a positive Dithionate/Hemoglobin Solubility Test look like?
Marked turbidity
How is the Metabisulfite/Sickling Test performed?
-P.Smear for sickling after metabisulfite is added
What is the Kleihauer-Betke preparation used for?
Detection of HbF
How does the Kleihauer-Betke preparation work? (2)
Acid Elution
- HbA elutes from RBCs, HbF does not
- Cells with persistent eosinophilia contain HbF
Acid Elution technique (Kleihauer-Betke):
- Most common pattern?
- When is it seen? (2)
- What is the pattern in Hereditary Persitence of HbF (HPFH)
- Heterocellular pattern (some but not all cells w/ HbF)
- Fetomaternal hemorrhage
- Thalassemia
- Pancellular pattern in HPFH
What are Fast Hemoglobins?
-Most common? (2)
Migrate beyond HbA on alkaline gel
- HbH
- HbBarts
Band present in the S region on electrophoresis, but Sickle Screen is negative. What may this indicate? (3)
- HbD
- HbG
- Lepore
