I. Fundamental Hematology Principles

Whole Blood Includes…?

Erythrocytes, leukocytes, platelets, and plasma

Buffy Coat

Small white layer btn RBCs & plasma

• Appears when specimen is centrifuged

• Leukocytes and platelets

Plasma

Liquid portion of unclotted blood OR component produced when blood contains anticoagulant

Serum

fluid remaining after coagulation and a clot has formed

Plasma vs Serum

contains ALL coag factors vs LACKING fibrinogen group (I, V, VIII, XIII) coag proteins

Homeostasis

the process that maintains stable internal conditions in the body, including blood clotting and fluid balance.

Normal Osmotic Concentration

aka Isotonic = osmotic pressure is balanced with cells, preventing net movement of water.

Hypotonic Solution

• ↑ H2O, ↓ Solute conc.

• Cells swell → lyse

Hypertonic Solution

• ↓ H2O, ↑ Solute conc.

• Cells crenate

pH reference range: venous vs. arterial blood

• venous: 7.36-7.41

• arterial: 7.38-7.44

Body Temp Normal Range

37°C (97-99°F)

MCV (mean corpuscular volume) range, definition, and importance

• 80-100 fL

• avg. vol. of RBC

• ↑ = megaloblastic anemia, hemolytic anemia, liver disease, norm newborn

• ↓ = iron defic. anemia, thalessemia, sideroblastic anemia, lead poisoning

MCH (mean corpuscular HgB) range, definition, and importance

• 26-34 pg

• avg. weight of HgB in RBC

• ↑ = macroytic anemia

• ↓ = microcytic, hyperchromic anemia

MCHC (mean corpuscular HgB conc.) range, definition, and importance

• 32-37 g/dL

• avg. conc of HgB in RBC

• ↑ = error or spherocytes, hyperchromic

• ↓ = hypochromic RBCs → iron defic. and thalessemia

MCH (pg) formula

Hgb (g/dL) x 10 / RBC count ( x 10^12/L)

MCV (fL) formula

HCT (%) x 10 / RBC count (x 10^12/L)

MCHC (g/dL) formula

Hgb (g/dL) x 100 / Hct (%)

RBC indicies triangle

Hgb (Hemoglobin) Reference Range

Males: 13.5-17.5 g/dL

Females: 12.0-16.0 g/dL

Platelets Reference Range

150 - 450 × 10^9/L (150,000-450,000/uL)

MPV (mean platelet volume)

6.8 - 10.2 fL

*Note: MPV is analagous to MCV for RBCs

Relative vs Absolute Count

Proportion of a cell type in WBC count % vs. actual cells per blood volume #.

Relative Lymphocytosis

inc. in % of lymphocytes, associated w/ neutropenia

Absolute Lymphocytosis

inc. in # of lymphocytes

Relative vs Absolute polycythemia

increase in RBCs, distinguishing between % and actual # of cells.

• Most common: Wright stain

• Contains Methylene blue: basic dye that stains acidic (DNA and RNA) blue

• Contains Eosin: acidic dye that stains basic (Hgb and eosinophilic cytoplasmic granules) red-orange

• Methanol Fixative

• Phosphate Buffer: 6.4-6.8

Nonvital (dead cell) polychrome (Romanowsky)

Causes of RBCs too red and WBC nuclei poorly stained

< 6.4 pH, excess buffer, dec. staining time, inc. washing time, thin, expired stains

Causes of RBCs and WBC nuclei poorly stained

> pH 6.8, too little buffer, inc. staining time, poor washing, thick smear, inc. protein, heparinized blood sample

Nonvital Monochrome Stain

Ex: Prussian blue stain, used to identify iron granules

• New methylene blue: stains RNA in reticulocytes

  • Measure level of erythropoiesis

• Neutral red w/ brilliant cresyl green: visualize heinz bodies

  • shows G6PD deficiency, unstable HgB

Supravital Monochrome Stain