Prozone phenomenonSerial dilution

Titer

Ayed HatemBCs/KKU

• Prozone phenomena

• In an agglutination or precipitation reaction,

the zone of relatively high antibody

concentrations within which no reaction

occurs. As the antibody concentration is

lowered below the prozone, the reaction

occurs.(solve by dilution)

• This phenomenon may be due simply to

antibody excess or it may be due to blocking

antibody or to nonspecific inhibitors in serum.

Precipitation Curve

An example of prozone

phenomenon.

* Sample 2 is an example of the prozone phenomenon

Serial dilution

Serial Dilution

We then transfer 1 ml of the original solution into the tube with 9ml of water.Now, We have 1 ml (sample) + 9 ml (Water)=10

What is the concentration in tube #3?

To Find The Concentration in Tube # 3

Cont..

Continue

Constant Formula

Titer

Titration

• is a semi-quantitative method used to determine the concentration of antibody in a serum sample or to compare the strength of antigen expression on different samples.

• Speed and strength of agglutination is termed as avidity.

Titers

• TITERS are reported out as the reciprocal of the last tube giving a positive reaction.

• So if tube 2 was the endpoint, the dilution is 1:800 the titer is reported out as 800/1= 800.

The end..