What indicates the presence of memory B cells in an immune response test?

The presence of memory B cells in an immune response test is indicated by faster production of antibodies compared to the first injection. When an individual is exposed to a specific antigen for the first time, it usually takes time for the immune system to recognize the pathogen, proliferate the appropriate B cells, and produce antibodies, which is known as the primary immune response.

Once this initial response has occurred, some of those B cells differentiate into memory B cells. These cells persist in the body long after the initial infection has been cleared. If the same antigen is encountered again, memory B cells are able to respond rapidly and more effectively, leading to a faster and more robust antibody production known as the secondary immune response. This swift reaction not only provides a more effective defense but also illustrates the memory capability of the adaptive immune system.

In summary, the ability to produce antibodies quickly upon re-exposure to an antigen is a hallmark of the existence of memory B cells, showcasing the enhanced immune response facilitated by these specialized cells.