May 20, 2024

Enumeration of white blood cell (WBC) count

Enumeration of white blood cell (WBC) count

Introduction

White blood cell count is an enumeration of white corpuscles or a leucocyte count. The white blood cells (WBCS)or leucocytes are nucleated actively amoeboid, do not contain haemoglobin, and originated purely from extravascular tissue. They are composed of nucleoproteins and varieties of enzymes. Their number is less and their life span is short compared to red blood cells. The WBCs exist in two forms viz. granulocytes and agranulocytes. Granulocytes are further classified as eosinophil, basophil, and neutrophil, while agranulocytes show lymphocytes and monocytes. These varieties possess independent morphological, functional and staining properties. The main function of white blood corpuscles is phagocytosis which is the body’s defence mechanism against foreign particles and invading bacteria. They are also involved in antibody formation in the immunological body defence mechanisms. It also takes part in the process of repair in an area of inflammation.

The basic principle is that the blood is diluted with an acid solution which removes the red cells by haemolysis and also accentuates the nuclei of the white cells; thus the counting of the white cells becomes easy. Blood cell counts can be performed using the hemacytometer.

Significance

The white cell count is the number of white cells present in one cubic millimetre of blood. The normal values of white blood cell count vary between 5000 to 10,000 per cubic millimetre or 7-11 thousand cells/µl of blood volume in healthy individuals.

Variation in normal values is observed in diseased states. WBC count increases (leucocytosis) in conditions like pneumonia, leukaemia, meningitis, smallpox etc. while the count decreases (leucopenia) in conditions such as influenza, typhoid, infectious hepatitis etc. Moreover, the count rises in pregnancy and during menstruation. Thus, white blood cell count is useful in diagnosis.

The aim of the experiment is to estimate the white blood cell count of a blood specimen.

Requirements

Neubauer chamber, WBC pipette, Coverslip, WBC diluting fluid, Needle, spirit, cotton.

Procedure

  1. Sterilize the fingertip with a cotton plug soaked in 70% alcohol and let it dry.
  2. Take a bold prick to have a free flow of blood and draw the blood in a WBC pipette up to the 0.5 mark.
  3. Dip the WBC pipette in WBC diluting fluid up to the 11 mark and rotate the pipette equally in your hands to mix the solution well by swirling.
  4. Take the haemocytometer and place it on the flat surface of the workbench. Place the cover slip on the counting chamber.
  5. Allow a small drop of diluted blood, hanging from the pipette, to sweep into the counting chamber by capillary action. Make sure that there is no air bubble and there is no overfilling beyond the ruled area.
  6. Leave the counting chamber on the bench for 3 minutes to allow the cells to settle. Observe the cells by placing the counting chamber on the mechanical stage of the microscope.

Focus on one of the corner squares of the counting chamber and count the white cells schematically, starting from the upper left small square of each Square. Repeat the count in all four corners of the chamber. Apply the margin rules i.e. count the cells lying on two adjacent margins, and discard those on the other two margins

Data Analysis

No. of cells * Dilution factor * Depth factor / Area count
Where:
Dilution factor = 20, Depth factor = 10, Area count = 4

Result

The number of white blood cells present in one µl of the blood specimen is _____

Interesting facts

Interesting facts about White blood cell WBC

Types of White Blood Cells: There are several types of white blood cells, including neutrophils, lymphocytes, monocytes, eosinophils, and basophils. Each type has specific functions in combating different pathogens.
Lifespan: White blood cells have a relatively short lifespan compared to other cells in the body. Most white blood cells live for only a few days to a couple of weeks.
Production: WBCs are produced in the bone marrow through a process called hematopoiesis. Stem cells in the bone marrow differentiate into different types of white blood cells based on the body’s needs.
Function: White blood cells primarily function to defend the body against infections. They recognize and destroy foreign invaders, such as bacteria, viruses, and fungi, through various mechanisms like engulfing them, producing antibodies, and releasing chemicals to kill pathogens.
Movement: White blood cells can move actively throughout the body by squeezing through the walls of blood vessels, a process called diapedesis. This allows them to reach the site of infection or inflammation.
Phagocytosis: Some white blood cells, particularly neutrophils and monocytes, are phagocytes. They engulf and digest bacteria, cellular debris, and other foreign substances through a process called phagocytosis.
Immune Response: Lymphocytes, a type of white blood cell, are the key players in the immune response. They are responsible for recognizing specific antigens and coordinating the body’s immune response, including the production of antibodies.
Leukocytosis and Leukopenia: Abnormal levels of white blood cells can indicate underlying health conditions. Leukocytosis is an increase in WBC count, often seen in response to infections, while leukopenia is a decrease in WBC count, which can be caused by certain medications, diseases, or bone marrow disorders.
Allergies and Eosinophils: Eosinophils are white blood cells involved in allergic reactions and parasitic infections. They release substances that help regulate the immune response during allergic reactions.
Diagnostic Importance: Measuring the number and types of white blood cells in a blood sample, known as a complete blood count (CBC), is a common diagnostic tool to assess a person’s overall health and detect underlying conditions.

How to calculate WBC in neubauer chamber

Calculation: Once the WBCs have been counted in the designated squares, calculate the average number of WBCs per square. This is done by dividing the total number of cells counted by the number of squares observed. Multiply the average count by a factor based on the dilution ratio to obtain the WBC count per microliter (μL) or milliliter (mL) of the original blood sample.
Final Result: Report the calculated WBC count as the number of cells per microliter (or milliliter) of blood.


Human Anatomy and Physiology Practical Syllabus

  1. Study of a compound microscope.
  2. Microscopic study of epithelial and connective tissue
  3. Microscopic study of muscular and nervous tissue
  4. Identification of axial bones
  5. Identification of appendicular bones
  6. Introduction to hemocytometry.
  7. Enumeration of white blood cell (WBC) count
  8. Enumeration of total red blood corpuscles (RBC) count
  9. Determination of the bleeding time
  10. Determination of clotting time
  11. Estimation of haemoglobin content
  12. Determination of blood group.
  13. Determination of erythrocyte sedimentation rate (ESR).
  14. Determination of heart rate and pulse rate.
  15. Recording of blood pressure.

First Year B Pharm Notes, Syllabus, Books, PDF Subjectwise/Topicwise

F Y B Pharm Sem-IS Y B Pharm Sem-II
BP101T Human Anatomy and Physiology I TheoryBP201T Human Anatomy and Physiology II – Theory
BP102T Pharmaceutical Analysis I TheoryBP202T Pharmaceutical Organic Chemistry I Theory
BP103T Pharmaceutics I TheoryBP203T Biochemistry – Theory
BP104T Pharmaceutical Inorganic Chemistry TheoryBP204T Pathophysiology – Theory
BP105T Communication skills TheoryBP205T Computer Applications in Pharmacy Theory
BP106RBT Remedial BiologyBP206T Environmental sciences – Theory
BP106RMT Remedial Mathematics TheoryBP207P Human Anatomy and Physiology II Practical
BP107P Human Anatomy and Physiology PracticalBP208P Pharmaceutical Organic Chemistry I Practical
BP108P Pharmaceutical Analysis I PracticalBP209P Biochemistry Practical
BP109P Pharmaceutics I PracticalBP210P Computer Applications in Pharmacy Practical
BP110P Pharmaceutical Inorganic Chemistry Practical
BP111P Communication skills Practical
BP112RBP Remedial Biology Practical

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  • Pre-eclampsia and Screening: Identifying Risks for a Healthier Pregnancy

  • Exploring Sugar Substitutes like Neotame, Aspartame, and Saccharin