Sera from 43 patients were tested for complement-fixing antibodies to Borrelia burgdorferi; these patients included 8 with confirmed Lyme disease, 21 who were serologically positive but not likely to have Lyme disease, and 14 who were serologically negative. Seven individuals, all confirmed Lyme disease patients, had complement-fixing antibodies. Complement fixation may be a useful confirmatory...

Case 1 The following was received from an ophthalmologist concerning a 46-year-old patient: "He has left hyalitis, which is secondary to cyclitis. The gonococcal complement-fixation test was weakly positive. I have told the patient the result of the blood test." The patient's wife had left him after hearing the diagnosis but later returned to him. So many positive gonococcal complement-fixation...

Influenza complement fixation tests designed for use with ferret serum are described. Complement-fixing antigens derived from influenza ferret lungs were unsatisfactory due to their low content of soluble antigen; those prepared from mouse lungs or developing chick embryo membranes proved to be better antigenically and were reliable when the various reagents in the test were properly adjusted t...