| enzyme-linked immunosorbent assay | An immunoassay utilizing an antibody labelled with an enzyme marker such as horseradish peroxidase. While either the enzyme or the antibody is bound to an immunosorbent substrate, they both retain their biologic activity; the change in enzyme activity as a result of the enzyme-antibody-antigen reaction is proportional to the concentration of the antigen and can be measured spectrophotometrically or with the naked eye. Many variations of the method have been developed. (12 Dec 1998) |
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| tumour stem cell assay | <investigation> A cytologic technique for measuring the functional capacity of tumour stem cells by assaying their activity. It is used primarily for the in vitro testing of antineoplastic agent. (12 Dec 1998) |
| factor II assay | A test used to measure the activity of a blood clotting factor (thrombin). This test may be used to evaluate excessive bleeding. Abnormally low factor II assays may be seen in the following conditions: congenital deficiency of factor II, fat malabsorption, heparin administration, cirrhosis, vitamin K deficiency and warfarin administration. (27 Sep 1997) |
| factor ix assay | A test used to measure the activity of a blood clotting factor IX (Christmas factor). This test may be used to evaluate excessive bleeding. Abnormally low factor IX assays may be seen in the following conditions: congenital deficiency of factor IX, fat malabsorption, heparin administration, cirrhosis, vitamin K deficiency and warfarin administration. (27 Sep 1997) |
| factor v assay | A test used to measure the activity of a blood clotting factor V. This test may be used to evaluate excessive bleeding. Abnormally low factor V assays may be seen in the following conditions: congenital deficiency of factor V, DIC, heparin administration, cirrhosis and primary fibrinolysis. (27 Sep 1997) |
| factor vii assay | A test used to measure the activity of a blood clotting factor VII. This test may be used to evaluate excessive bleeding. Abnormally low factor VII assays may be seen in the following conditions: congenital deficiency of factor VII, fat malabsorption, heparin administration, cirrhosis, vitamin K deficiency and warfarin administration. (27 Sep 1997) |
| factor viii assay | A test used to measure the activity of a blood clotting factor VIII (Von Willebrand factor). This test is usually used to monitor treatment of haemophilia. Abnormally low factor VIII assays may be seen in the following conditions: congenital deficiency of factor VIII (haemophilia), DIC and secondary fibrinolysis. This test may also be performed in the evaluation of Von Willebrand's disease. (27 Sep 1997) |
| factor x assay | A test used to measure the activity of a blood clotting factor X. This test may be used to evaluate excessive bleeding. Abnormally low factor X assays may be seen in the following conditions: congenital deficiency of factor X, fat malabsorption, heparin administration, cirrhosis, vitamin K deficiency and warfarin administration. (27 Sep 1997) |
| factor xii assay | A test used to measure the activity of a blood clotting factor XII. This test may be used to evaluate excessive bleeding. Low factor XII may be seen in cases of congenital deficiency of factor XII, heparin administration and liver disease. (27 Sep 1997) |
| Farr type assay | <investigation> Method of radioimmunoassay in which free antigen remains soluble and antibody antigen complexes are precipitated. (18 Nov 1997) |
| 17-ketogenic steroid assay test | A colourimetric test, based on the Zimmermann reaction, which indicates metabolites or adrenal and testicular steroids excreted as 17-ketones in the urine; increased values are most striking in adrenocortical tumours, decreased values in Addison's disease or in panhypopituitarism. Synonym: ketogenic corticoids test. (05 Mar 2000) |
| focus-forming assay | <investigation> A lab technique used to find out if a particular piece of DNA contains oncogenes (genes which are associated with cancer). This is done by putting the DNA into animal cells which normally show contact inhibition, or which stop growing when they come into physical contact with other cells or reach a certain density in the culture. If the cells lose contact inhibition and form areas of densely-packed cells (called foci) after receiving the DNA, it means that the DNA did contain oncogenes. (05 Jan 1997) |
| leukocyte adherence assay test | A test to detect the ability of leukocytes to adhere to bacteria, performed in vitro using nylon fibres to measure adherence. (05 Mar 2000) |
| leukocyte bactericidal assay test | A test of leukocytes to determine their ability to kill a culture of live bacteria. (05 Mar 2000) |
| LH assay | A blood test which measures the amount of luteinising hormone (LH). LH is a protein hormone that is secreted by the anterior pituitary gland. In women, a surge in LH at midcycle causes ovulation. For the next 7-10 days LH maintains the corpus luteum which synthesises progesterone. The corpus luteum disintegrates after about 10 days if fertilization does not occur. In men, LH stimulates production of testosterone by the Leydig cells in the testes. This test may be used to evaluate anovulatory bleeding, infertility, ovarian cysts and multiple endocrine neoplasia (MEN) I. Normal values in males: 7 to 24 U/L. Normal values in females: greater than 6-30 U/L. Greater than normal values can indicate: anorchia, hypogonadism, Klinefelter syndrome, menopause, ovarian failure, polycystic ovary disease, precocious puberty and Turner's syndrome. Lower than normal values can indicate hypopituitarism. (27 Sep 1997) |