Microbiology

Question 1

Defence mechanisms?

Answer 1

Natural defense mechanism:
- species
- racial
- individual
- external ( skin, eye, gastrointestinal tract, urogenital tract, mouth, sebaceous glands, acid in stomach)

Internal defense mechanism:
-non specific immunity
- specific acquired immunity

Question 2

Types of Immunity?

Answer 2

1) Innate or natural
– nonspecific
– specific

2) Acquired
– Active: natural: after clinical infection
: artificially stimulated: vaccine
– Passive: natural: from mother
: artificially stimulated: Sera, immunoglobin

Question 3

Phagocytes types

Answer 3

Microphages- polymorphonuclear leucocytes - neutrophils
Macrophages- histiocytes- monocytes

Question 4

Properties of antigens

Answer 4

1- macromolecular size
2- foreignness
3- solubility and susceptibility
4- chemical nature and complexity (high✓)
5- antigenic specificity
- species specificity
- isospecificty
- autospecificity
- organ
- heterophile

Question 5

Monoclonal antibodies

Answer 5

Definition- Antibody produced by a cell clone derived from a fusion of one antibody producing cell with one myeloma cell. Such a fused cell which was originally describe as hybrid- myeloma was named as hybridoma.

Question 6

Preparation of monoclonal antibodies

Answer 6

Monoclonal antibodies are mainly produced by hybridoma technology

• Immunization of mice with immunogen
• Fusion of plasma cells with myeloma cells
• Selection of hybrid cells
• growth and cloning of hybrid cells
• purification and storage of hybridi cells
• human monochromal antibody