👉 The Bradley fluid, also known as Bradley's fluid or Bradley's serum, is a colloidal suspension of proteins and other macromolecules, primarily composed of immunoglobulins (antibodies) and complement proteins, in a water-based solution. Discovered by Richard Bradley in 1945, this fluid is notable for its ability to resist sedimentation due to the presence of these large, charged molecules that form a protective layer around each other, preventing them from settling. This unique property makes it useful in various medical and research applications, such as in the study of immune responses and as a model for understanding protein behavior in biological systems.