Clinical chemistry refers to the processes used to measure levels of biochemical components in bodily fluids such as serum and plasma. This data domain contains parameters related to lipid metabolism in the liver and kidneys, and to hormone (e.g., thyroid) and electrolyte (e.g., potassium) levels.
Developmental toxicity refers to the adverse effects on the developing organism. This data domain contains information relating to prenatal and developmental assessments. Examples of endpoints: fetal examination, markers of puberty (e.g. vaginal opening), and neuromuscular (e.g., grip strength) and neurobehavioral (e.g., motor activity) endpoints.
The bacterial mutagenicity test, or Ames Assay, is used to assess whether a test article causes genetic damage. These data are bacterial colony counts.
The in vitro micronucleus assay provides insight into the genotoxic damage potential of test articles by measuring the frequency of micronuclei in mammalian cell cultures. Flow cytometry is commonly used to measure DNA damage in cell cultures by counting harvested cells to determine the percentage of cells that are micronucleated. In vitro micronucleus data can include cell counts, percentages of micronucleated cells, and percentages of apoptotic cells.
The in vivo comet assay examines the ability of substances to cause DNA damage in cells from a variety of different tissues in an organism, such as stomach, liver, lung, or brain. The DNA damage detected in the comet assay may be in the form of breaks or adducts, as well as transient damage resulting from normal DNA repair processes.
The peripheral blood erythrocyte micronucleus test provides an indication of whether a test article is capable of inducing structural and/or numerical chromosomal damage, specifically micronuclei damage. This data domain contains the frequency of micronucleated erythrocytes (red blood cells) in either bone marrow or peripheral blood in response to exposure to a test article.
Gross observations identify the morphologic alterations in tissues that are visible without the aid of a microscope. This data domain includes changes in organs observed, terminal body weight, and absolute and relative organ weights at necropsy.
Hematology is the analysis of cells that circulate in the bloodstream – namely red blood cells, white blood cells, and platelets. Hematology analysis is done on whole blood and includes a complete blood count (CBC) and blood smear evaluation. Examples of endpoints: cell counts, red blood cell size, and hemoglobin concentration.
The Toxicology in the 21st Century (Tox21) program is a federal collaboration that uses automated high throughput screening (HTS) methods to quickly and efficiently test chemicals for activity across a battery of assays that target cellular processes. These assays rapidly evaluate large numbers of chemicals to provide insight on potential human health effects.
Histopathology is the study of microscopic changes or abnormalities in tissues. This dataset domain contains descriptions of tissue abnormalities (diagnosis), site of abnormality (location), and severity of lesions. Examples of endpoints: diagnosis, distribution, and severity of lesions, and indication of whether the observed lesion is neoplastic, metastatic, systemic, or malignant.
Immunotoxicology identifies the potential for a test article to modulate immune function in mice and/or rats. This data domain contains studies that evaluate the basic functional aspects of diverse immune system components including innate immune function and adaptive immune function (humoral mediated immunity, cell-mediated immunity). Examples of endpoints: function (phagocytosis), natural killer cell assay, cytotoxic T lymphocyte activity, proliferative responses that signal through the T cell receptor, IgM and IgG antibody production following challenge with T-dependent antigens, and quantification of leukocyte populations.
In-life observations are recorded during the exposure period of a study and describe individual animal’s response to test article. Examples of endpoints: body weight measurements, clinical observations, food and water consumption, and body temperature measurements.
Toxicogenomics studies that employ microarrays evaluate the biological response to a toxicological challenge at the level of the genome. Results from these studies are typically reported as gene and molecular pathway read outs, which can be further analyzed for their relationship to toxicity and disease outcomes. Datasets are provided as raw, probe-level files including CEL files (Affymetrix arrays) and TXT files (CodeLink or Agilent arrays).
Toxicogenomics studies that employ the polymerase chain reaction (PCR) technique evaluate the biological response to a toxicological challenge at the level of individual genes or a small set of genes. PCR is often used to test specific gene-level hypotheses related to a toxicological challenge or validate results from larger scale microarray studies. Data are reported as the expression of a number of genes related to toxicology under different conditions.
Reproductive toxicity describes the adverse effect of test articles on fertility and fecundity. This data domain contains data relating to the fertility, gestation, and number of live offspring. Examples of endpoints: estrous cyclicity, sperm parameters, live pup counts per litter, and pup sex ratio.
The purity data is for the NTP Tox21 Phase 2 chemicals provided to NCATS for the Tox21 Phase 2 program. This data results from the analysis of neat chemicals, prior to the preparation of the DMSO solutions sent to NCATS and should not be equated with NCATS QC Day 0 or QC Day 4 data. Tox21 Phase 2 Purity Data is also available at NTP Data Collections Guided Search: https://cebs.niehs.nih.gov/datasets/search/tox21
Urinalysis measures the physical, biochemical, and microscopic properties of urine. A urinalysis includes gross examination of urine for color and clarity and measurements of urine volume and specific gravity. This data domain contains data relating to levels of electrolytes, proteins, and enzymes. Examples of biochemical endpoints: levels of glucose, creatinine, protein, and sodium.