Deck 14

Question 1

Disadvantages of IFA

Answer 1

requirement of expensive equipment and reagents and trained personnel

• Green Fluorescence –> live cells
• Red Fluorescence –> dead cells

Question 2

Name parameters measured by FACS (Fluorescence-activated cell scanner)

Answer 2

• Size of cell
• Granularity of cell
• Intensity of fluorescence – detectors of fluorescens
• Identification of immune cells –> detection of CD4+ and CD8+ T-lymphocytes
• Also typical CD markers on the leukocytes: CD4 and CD8 T-lymhocytes

Question 3

Granularity of cells in flow cytometry are detected by

Answer 3

Side scatter

Question 4

Separation of leukocytes

Answer 4

• Immunologically non-specific: size, density, electric charge, and adherence abilities
• Immunologically specific: CD markers

Question 5

Separating solutions have specific density

Answer 5

1,077 – 1,079 g/cm3

• Granulocytes with pappenheim –> Purple / red
• Agranulocytes –> pale pink / pale colour / don’t stain

Question 6

Calculate the IPHA, index of phagocytic activity, if there are 340 particles per 100 phagocytes

Answer 6

• IPHA = 340 / 100 = 3,4
• Respiratory burst: Activated phagocytes produce different antimicrobial and cytotoxic substances which can destroy ingested microorganisms. Mechanisms of killing dependent on oxygen – forming of free oxyden radicals

Question 7

Defect in phagocyte function are related to

Answer 7

• Defects in mobilisation of leukocytes from their depots in bone marrow
• Lack of receptors for chemotactic factors
• Lack of adhesion molecules
• Lack of generation of bactericidal agents to destroy bacteria

Question 8

Failure of phagocytes results in

Answer 8

• Retarded growth
• Recurrent infections that tend to be prolonged
• Lymphadenopathy –> swelling of one or more lymph nodes

Question 9

How long is blood incubated with distilled water to get hypotonic solution?

Answer 9

35-40 seconds

Question 10

Compliment fixation test – what is detected?

Answer 10

If patient has antibodies specific to Ag