	Red BLOOD CELLS
	Red blood cell count
	Hematocrit
	Red cell indices
	Erythrocyte sedimentation rate
	Reticulocyte count
	Osmotic fragility
	HEMOGLOBIN
	Total hemoglobin
	Fetal hemoglobin
	Hemoglobin electrophoresis
	Sickle cell test
	Unstable hemoglobin
	Heinz bodies
	Iron and total iron-binding capacity
	Ferritin
	Methemoglobin
	WHITE BLOOD CELLS
	White blood cell count
	White blood cell differential
	PLATELET ACTIVITY
	Bleeding time
	Platelet count
	Capillary fragility
	Platelet aggregation
	COAGULATION
	Activated partial thromboplastin time
	Prothrombin time
	Activated clotting time
	One-stage factor assay:Extrinsic coagulation system
	One-stage factor assay:Intrinsic coagulation system
	Plasma thrombin time
	Plasma fibrinogen
	Fibrin split products
	Plasma plasminogen
	Protein C
	Euglobulin lysis time
	D-Dimer
	International normalized ratio

White Blood Cell Differential

Also known as: Differential leukocyte count, Peripheral differential, White blood cell morphology, WBC differential, Diff
Formal name: White Blood Cell Count Differential

The white blood cell (WBC) differential is used to evaluate the distribution and morophology of WBCs, providing more specific information about a patient's immune system than the WBC count alone.

WBCs are classified as one of five major types of leukocytes - neutrophils and monocytes - and the percentage of each type is determined. ho differential count is the percentage of each type of WBC in the blood. The total number of each type of WBC is obtained by multiplying the percentage of each type by the total WBC count

High levels of these leukocytes are associated with various allergic diseases and reactions to parasites. An eosinophil count is sometimes ordered as a follow-up test when an elevated or depressed eosinophillevel is reported.

Purpose

To evaluate the body's capacity to resist and overcome infection.
To detect and identify various types of leukemia.
To determine the stage and severity of an infection.
To detect allergic reactions.
To assess the severity of allergic reactions (eosinophil count).
To detect parasitic infections.

Patient preparation

Explain to the patient that this test is used to evaluate the immune system. . Review the patient's history for use of medications that may interfere with test results, including methysergide, desipramine, indomethacin, procainamide, anticonvulsants, capreomycin, cephalosporins, D-penicillamine, gold compounds, isoniazid, nalidixic acid, novobiocin, para-aminosalicylic acid, paromomycin, penicillins, phenothiazines, rifampin, streptomycin, sulfonamides, and tetracyclines. If these medications must be continued, note this on the laboratory slip.
Tell the patient that a blood sample will be taken. Explain who will perform the venipuncture and when.
Inform the patient that he needn't restrict food or fluids but should refrain from strenuous exercise for 24 hours before the test.
Reassure the patient that drawing a blood sample will take less than 3 minutes.
Explain that he may feel slight discomfort from the tourniquet pressure and the needle puncture.

Procedure and posttest care

Perform a venipuncture, collecting the sample in a 7-ml lavender-top tube.
If a hematoma develops at the venipuncture site, apply warm soaks

Precautions

Completely fill the collection tube; invert it gently several times to thoroughly mix the sample and the anticoagulant; to prevent hemolysis, do not shake the tube

Reference values

For normal values for the five types of WBCs classified in the differential for adults and children. For an accurate diagnosis, differential test results must always be interpreted in relation to the total WBC count.

Abnormal findings

Abnormal differential patterns provide evidence for a wide range of disease states and other conditions

Interfering factors

Failure to completely fill the collection tube, to use the proper anticoagulant, or to adequately mix the sample and the anticoagulant Hemolysis due to rough handling of the sample
Methysergide, desipramine, indomethacin, procainamide, anticonvulsants, capreomycin, cephalosporins, D-penicillamine, gold compounds, isoniazid, nalidixic acid, novobiocin, paraaminosalicylic acid, paromomycin, penicillins, phenothiazines, rifampin, streptomycin, sulfonamides, and tetracyclines.

The information provided on this web site should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed physician should be consulted for diagnosis and treatment of any and all medical conditions. We will not be liable for any complications, or other medical accidents arising from the use of any information on this web site.