Lab routine infection

• Leukocyte Count (White Blood Cell Count)


  The number of white blood cells per Litre of whole blood (System International Units) or per ml of whole blood (Conventional Unit)
• Leukocyte Count (White Blood Cell Count)

  1. Dilution of blood with acid solution

  2. Counting leukocytes in Neubauer chamber

  3. Calculation of leukocyte count
• Leukocyte Count (White Blood Cell Count)


  • Possible errors: Instrument, Technique, Specimen
• Normal WBC count (Adult)

  4 – 11 x 10^6/L or 4,000 – 11,000/µL
• Differential White Blood Cell Count


  Determining the relative number of each type of white blood cell present in the blood
• Differential White Blood Cell Count

  1. Making blood film

  2. Staining blood film with Giemsa

  3. Examining and counting different types of leukocytes
• From the blood smear, we can also estimate hemoglobin, as well as the size, shape and the structure of WBC
• Estimating the number of white blood cells (WBC)


  1. Estimate the number of WBC to the amount of RBC

  2. If the WBC count is not in conformity, the WBC count should be repeated
• Inspecting the blood film


  1. Inspect the blood film from the head to the tail

  2. Bigger cells like monocytes and neutrophils lie in the tail

  3. Smaller cells like lymphocytes predominate in the centre or the head of the blood film
• Inspecting the blood film under oil immersion

  1. Inspect the film on the part that there is no overlap of the red cells

  2. Place one drop of oil immersion

  3. Use the high power (objective 100x)
• Counting the various shapes of leukocytes

  1. Count the various shapes of leukocytes per 100 cells on the narrow field in a strip running the whole length of the film

  2. Report the result as a percentage

  3. For patients with very high counts, count the cells in any well spread area where the cell types are easy to identify
• Fig 3 shows Various Types of WBC
• Fig 4 shows (A) Toxic Granulation and Vacuolization of Neutrophil and (B) Atypical lymphocyte ("Limfosit Plasma Biru") and Kissing Cell (Reactive lymphocyte)
• Possible Errors in Blood Smear Technique

  • Drop of blood too large or too small
  • Spreader slide pushed across the slide in a jerky manner
  • Failure to keep the entire edge of the spreader slide against the slide while making the smear
  • Failure to keep the spreader slide at the proper angle with the slide
  • Failure to push the spreader slide completely across the slide
  • Delay in fixing the blood smear after air drying can cause abnormal morphology of erythrocyte
• Possible Errors in Staining

  • The staining rack must be exactly level
  • Insufficient washing
  • Excessive rinsing of the stained smear will cause the stain too fade
• Benign neutrophilia


  • Occurs most often in such condition as stress, tachycardia, fever, strenuous exercise and ingestion of certain medication
  • Toxic granulation of neutrophil showed reactivity of neutrophil against germ especially bacteria and vacuolization showed the phagotization process
• Eosinophilia


  Seen commonly in a wide spectrum of allergic responses, medication, many skin diseases, parasite infestation and malignancy
• Monocytosis


  • Seen whenever there is an increase amount of cell damage such as recovery from an infection
  • Some monocytes have vacuolization as phagocytes
• Relative lymphocytosis


  Can sometime be seen in patients with exanthems from certain viral diseases such as measles and mumps; and in patients convalescencing from certain acute infections
• The Westergren method has been chosen as the standard method by the International Committee for Standardization in Hematology (ICSH)
• Erythrocyte Sedimentation Rate (ESR) using Westergren method

  1. Mix the specimen until homogenous

  2. Clean the Westergren tube and dry

  3. Fill the Westergren pipette to exactly the 0 mark

  4. Place the pipette in the rack in vertical position and keep out of sunlight

  5. Allow the pipette to stand for about 60 minutes

  6. Record how many millimeters the red blood cells fallen
• Normal ESR: Female 0 - 20 mm/hr, Male 0 - 15 mm/hr
• Increased ESR


  Indicates inflammatory process, bacterial infection, certain neoplasm or tissue injuries-related process
• CRP latex test is used to detect and semi-quantify C-reactive protein (CRP) in serum
• Qualitative CRP latex test


  1. Place sample, negative control, positive control, and latex reagent on a slide

  2. Mix and spread the mixture over the slide

  3. Rotate the slide and check for agglutination after two minutes

  4. Agglutination will occur at concentration of CRP higher than 6 mg/L
• Semi-quantitative CRP latex test

  1. Prepare diluted samples using diluted solvent

  2. Make and check serial dilutions of the serum until agglutination does not occur

  3. The amount of CRP can be determined from the highest dilution at which agglutination occurs
• Normal CRP in serum: up to 6 mg/L
• CRP is an acute phase reactant used as a sensitive indicator for inflammation, infection, and tissue necrosis
• Monitoring CRP levels


  Indicates the effectiveness of treatment and the assessment of diseases progression
• The feedback form covers aspects done well, aspects to improve, and follow-up actions for both students and instructor