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Section A

1. Chemokines are low molecular weight cytokines which induces chemokinesis inleucocytes in inflammation.

2. To study the gene expression by detection of RNA in a sample3. Immunodiffusion is a technique to study between antigen and antibodies by observing

the formation of precipitation which results from the combination of specifc antigen or

antibody wherease immunoelectrophoresis is a method to determine the blood levels of

three major immunoglobulin, IgG, IgA, IgM.

4. Agar is a crude agar extracted from seaweed which contain agarose and agaropectin.Agarose is a highly purified which are obtained by removal of agaropectin in agar.

Agarose is usually used in immunodiffusion and immunoelectrophoresis.

5. Antiserum contain the whole host (non-specific antibodies) of natural immunoglobulin,while antibody only used to detected specific antigen in a sample.

6. Precipitin ring formed when antigen migrate from the well into the agarose after thereaction between the antibody and antigen.

7. To detecting cytokines or other soluble mediators secreted from a variety of differentcell type

8. A cytokine is a small protein released by cells that has a specific effect on theinteractions between cells, on communications between cells.

9. Precipitin is an antibody that form precipitation when react with antigen whileagglutinin is antibody which causes agglutination.

10.RT-PCR Reverse Transcription Polymerase chain reactionRIEP Rocket immunoelectrophoresis

Section B

1.

There are two types of immunodiffusion, radial immunodiffusion and doubleimmunodiffusion. Both are carried out in a small semisolid medium such as agar.

In Radial immunodiffusion, an antigen sample is placed in a well and allowed to diffuse

into agar containing a suitable dilution of an antiserum. The antigen will diffuse into the

agar. Initially, as the antigen diffuse out of the well, its concentration is relatively high

and soluble antigen-antibody adducted are forms. However, as Ag diffuses farther from

the well, Ag-Ab complex react with more antibody resulting to the formation of a ring of

precipitation, a precipitin ring forms around the well. The area of the precipitin ring is

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proportional to the concentration of antigen. By comparing the area of the precipitin

ring with standard curve, the concentration of the antigen sample can be determined.

In Double immunodiffusion, both antigen and antibody diffuse rapidly from wells

toward each other, thereby establishing a concentration gradient. As equivalence is

reached, a visible line of precipitate, a precipitin line forms. This assay is frequently used

for comparing different antigen preparation. In this test, different antigen preparation,each containing single antigenic species allowed to diffuse from separate wells against

the antiserum. Depending on the similarity between the antigens, different geometrical

patterns are produced between the antigen and antiserum wells. Three patterns can be

observed. Pattern of identity occurs when antibodies in the antiserum react with both

the antigens resulting in a smooth line of precipitate. The two antigens are identical.

Patter of partial identity occurs when the antibodies in the antiserum react more with

one of the antigens than the other. Spur like results are observed. Pattern of Non-

Identity occurs when none of the antibodies in the antiserum react with the antigenic

determinants. This shows that the two antigen are immunologically unrelated.

2. There are two types of immunoelectrophoresis, rocket immunoelectrophoresis (RIEP)and counter-current electrophoresis. RIEP is a simple, quick and reproducible method

for determining the concentration of antigen in an unknown sample. Various

concentration of antigen are loaded in agarose gells well. On electrophoresis,the

antigen begins to migrate toward anode and interact with the antibody molecules to

form a soluble antigen-antibody complex. When the equivalent point is reached, the Ag-

Ab complex precipitates and this precipitin line is seen in the form of a rocket. Higher

the amount of antigen loaded in the well, farther the antigen will travel through the gel.

When antigen concentration is increased, the height of the rocket increases.

Counter-current immunoelectrophoresis is a rapid version of double immunodiffusion

technique. This technique used to check antisera for the presence and specificity ofantibodies for a particular antigen. Ag-Ab complex form a precipitin line like double

immunodiffusion. When precipitin line forms, this indicates the presence of antibody in

the antigen of the sera while if more than one precipitin line formed, this indicate the

heterogenicity of the antibody for the antigen in the test sera.