(1) Autopsies, considered in the past the gold standard for diagnosis, have been replaced by serology , imaging, biopsies, and other studies.(2) Rheumatologists tend to rely on clinical signs, symptoms, and serology , whereas neurologists rely more on histopathology in order to exclude other myopathies.(3) Other frequently performed tests included histopathologic studies on tissues, blood typing, syphilis serology , and 2 components of drugs of abuse testing.(4) The diagnosis of brain abscess mandates other studies seeking the etiology, which may include HIV serology , sinus studies, and transesophageal echocardiogram.(5) However, a nasopharyngeal aspirate is the best specimen for detecting influenza viruses, and polymerase chain reaction is more sensitive than tissue culture when serology is the reference standard.(6) The diagnosis is particularly challenging, because serology and skin testing are not reliable in immunocompromised patients, emphasizing the need for accurate histologic identification.(7) If susceptibility or recent infection is indicated by serology , weekly ultrasound examinations should be performed for four to eight weeks after exposure (or two to six weeks after infection) to detect hydrops.(8) Laboratory diagnosis is primarily by serology , although antigen detection in tissue by immunohistochemistry and amplification of any RNA in blood and tissue can be used.(9) Blood sample for HIV serology and two sputum specimens were collected from each patient.(10) One has, therefore, to depend on serology for the diagnosis of the disease.(11) Human papilloma virus serology is not sensitive, in that many infected women are not seropositive.(12) Hepatitis serology and blood cultures were unremarkable.(13) Diagnosis is based on clinical and neurophysiological findings, serology , and by identifying the organism or toxin.(14) The blood collected for HIV serology was allowed to clot for 30 min at room temperature.(15) The study of small group discussion of patient cases took place in a semester-long 3-credit junior/senior level undergraduate course in clinical immunology and serology with 67 students.(16) The diagnosis of acute or chronic pancreatitis and pancreatic cancer was determined using previously established criteria that incorporated symptoms, radiology, pathology, and serology .