<unk>  nitric test strip (Berkeley Test) showing colored scale of nitric oxide status - See article and jump to Cardiovascular Disease, Nitric Oxide: a<unk> ry biomarker for cardio-protection<unk>  or<unk> omics is a diagnostic technique that involves laboratory analysis of<unk>  to identify markers of endocrine, immunologic, inflammatory, infectious, and other types of conditions.<unk>  is a useful biological fluid for assaying steroid hormones such as cortisol, genetic material like RNA, proteins such as enzymes and antibodies, and a variety of other substances, including natural metabolites, including<unk>  nitrite, a biomarker for nitric oxide status (see below for Cardiovascular Disease, Nitric Oxide: a<unk> ry biomarker for cardio-protection).<unk>  is used to screen for or diagnose numerous conditions and disease states, including Cushing's disease, anovulation, HIV, cancer, parasites, hypogonadism, and allergies.<unk> ry<unk>  has even been used by the U.S. government to assess circadian rhythm shifts in astronauts before flight and to evaluate hormonal profiles of soldiers undergoing military survival training. Proponents of<unk>  cite its ease of collection, safety, non-invasiveness, affordability, accuracy, and capacity to circumvent venipuncture as the primary advantages when compared to blood<unk>  and other types of diagnostic<unk> . Additionally, since multiple samples can be readily obtained,<unk>  is particularly useful for performing chronobiological assessments that span hours, days, or weeks. Collecting whole<unk>  by passive drool has a myriad of advantages. Passive drool collection facilitates large sample size collection. Consequently, this allows the sample to be tested for more than one biomarker. It also gives the researcher the ability to freeze the left over specimen to be used at a later time. Additionally, it lessens the possibility of contamination by eliminating extra collection devices and the need to induce<unk>  flow. The clinical use of<unk>  occurred at least as early as 1836 in patients with bronchitis.<unk>  the acidity of<unk>  occurred at least as early as 1808. The<unk>  of<unk> tion by the use of mercury was performed at least as early as 1685. More recent studies have focused on detection of steroid hormones and antibodies in the<unk> . Recent applications emphasize the development of increasingly sophisticated techniques to detect additional proteins, genetic material, and markers of nutritional status. According to Wong, scientists are now viewing<unk>  as “a valuable biofluid…with the potential to extract more data than is possible currently with other diagnostic methods.”
Saliva testing
Nasal provocation test
Optometry
Oral microbiology
EOS imaging
Throat culture
Nasopharyngeal swab
Acoustic rhinometry