The concentration of antibodies in serum is expressed as the BLANK.
The Correct Answer and Explanation is :
The concentration of antibodies in serum is expressed as the titer.
Explanation:
An antibody titer is a measurement of the concentration of antibodies present in a serum sample. It is commonly used in clinical settings to assess the immune response to an infection or vaccination. The titer is determined by serially diluting the serum and then testing for the ability to bind or neutralize specific antigens, such as those from viruses or bacteria. The highest dilution of serum that still produces a measurable antibody response is considered the antibody titer.
In a laboratory setting, to determine the titer, a series of dilutions are made from the serum, and each dilution is tested for its ability to bind to a specific antigen. The titer is expressed as the reciprocal of the highest dilution that still yields a positive result. For example, if the highest dilution that gives a positive response is 1:256, the titer is reported as 256.
Clinical Significance:
Antibody titers are crucial in various medical fields, including immunology, infectious diseases, and vaccine efficacy. They help to assess:
- Immune status: A high titer may indicate a strong immune response to a pathogen or vaccine.
- Immunity levels: In vaccine development, determining the antibody titer is essential for understanding the effectiveness of a vaccine. For example, a titer test after a vaccination can confirm whether a person has developed immunity to a specific disease.
- Infection diagnosis: Titers can be used to diagnose infections, such as during an acute phase of illness or to check for past exposure to pathogens.
It’s important to note that titer values alone do not always correlate with immunity, and other factors, like the presence of memory cells or the function of antibodies, also play a role in long-term protection.