Introduction to Manual CBC Workflow

This flashcard set covers the fundamental concepts, vocabulary, and laboratory procedures for manual CBC workflows, including blood composition, manual cell counting, and WBC morphology.

Plasma

The liquid portion of the blood.

Formed elements

The solid portion of blood, consisting of RBCs, WBCs, and platelets.

Lavender top tube

The type of collection tube containing anticoagulant used for hematology testing.

Hemoglobin S

A form of hemoglobin commonly found in patients with sickle cell anemia.

Standard Turnaround Time (TAT)

$1$ hour for a Complete Blood Count (CBC).

Hemolysis

The rupture of red blood cells, which can be avoided during extraction by not applying excessive pressure.

Accessioning

The phase where a specimen is accurately registered in the work list or Laboratory Information System (LIS), often using bar codes.

Erythrocyte

An anucleate, biconcave, discoid cell filled with hemoglobin (HGB) that transports oxygen and carbon dioxide.

Thoma Pipette

A glass pipette used for manual blood dilution; the RBC version has a red bead, and the WBC version has a white bead.

Hemocytometer

A gridlined instrument used for manual cell counting of WBCs (corner squares), RBCs (center square), and platelets (all center squares).

Charging

The procedure of filling a hemocytometer with a diluted blood fluid.

$$1:200$$

The dilution ratio typically used for manual Red Blood Cell (RBC) counting.

Leukocytes

Also known as white blood cells (WBCs), these are cell types dedicated to protecting the host from infection and injury.

Glacial acetic acid

A dilute acid solution used as the diluent for manual WBC counting.

$$1:20$$

The dilution ratio typically used for manual White Blood Cell (WBC) counting.

Drabkin reagent

A reagent containing cyanide used to convert hemoglobin into stable cyanmethemoglobin (hemiglobincyanide) for measurement.

Hematocrit (Hct)

The ratio of the volume of packed RBCs to the total volume of whole blood.

Mean Corpuscular Volume (MCV)

An RBC index calculated as $\frac{Hct}{RBC} \times 10$ that reflects the average RBC diameter/size in femtoliters ($fL$).

Mean Corpuscular Hemoglobin (MCH)

An RBC index calculated as $\frac{Hgb}{RBC} \times 10$ that expresses the mass of hemoglobin in picograms ($pg$).

Mean Corpuscular Hemoglobin Concentration (MCHC)

An RBC index calculated as $\frac{Hgb}{Hct} \times 100$ that reflects the hemoglobin content and staining intensity in $g/dL$.

Wedge-prep

A technique for preparing a blood film on a glass microscope slide for examination.

Neutrophils

Phagocytic cells with multilobed nuclei (segmented) that engulf and destroy microorganisms.

Bands

Less mature neutrophils; an increase in these cells signals bacterial infection and is called a "left shift."

Eosinophils

White blood cells with bright orange-red, regular cytoplasmic granules involved in immune system regulation.

Basophils

White blood cells with dark purple, irregular cytoplasmic granules that contain histamines and obscure the nucleus.

Monocytes

The largest type of WBC with a dark purple nucleus shaped like a kidney bean, horseshoe, or lopsided circle.

Lymphocytes

White blood cells with a large, dark-staining nucleus and minimal cytoplasm that determine the specificity of the immune response.