The human body has at least a trillion ways of recognizing that something foreign has invaded.
Normally the trillions of lymphocytes in the human body do not attack their host.
The immune system recognizes invaders in a complex way.
This virtual lab teaches the procedures of performing an ELISA test to determine whether a particular antibody is present in a patient's blood sample.
Some organisms have evolved ways of evading or subverting the body's defenses.
A wide overview of the immune system, presented by HHMI investigators John W. Kappler, PhD, and Philippa Marrack, PhD