In Situ In situ ("in place" in Latin), a term used in: * biology, where it means to examine the phenomenon exactly in place where it occurs (without removing it in some special medium etc.). Usually means something intermediate between in vivo and in vitro. For example, examining a cell within a whole organ intact and under perfusion may mean in situ investigation. This is not obviously in vivo experiment because an animal is sacrificed, but it is not the same that to work with this cell alone (which may be a perfect case of in vitro experiment).
Carcinoma In Situ Carcinoma in situ is present when a tumor has been detected that has the characteristics of malignancy but has not invaded other tissues. Many forms of cancer are initially carcinomas in situ, but are not detected early enough.
Fluorescent In Situ Hybridization Fluorescent in situ hybridization (FISH) is a process which vividly paints chromosomes or portions of chromosomes with fluorescent molecules. A fluorescent hybridization probe is created for the DNA segment of interest. The probe, and attached fluorescent molecule, will combine with any complementary DNA or RNA it encounters.
This technique is useful for identifying chromosomal abnormalities and gene mapping. It can also be used to identify microorganisms.
Ductal Carcinoma In Situ/Temp Ductal carcinoma in situ (or DCIS) is the most common type of noninvasive breast cancer in women. Ductal carcinoma refers to the development of cancer cells within the milk ducts of the breast. In Situ means “in place” and refers to the fact that the cancer has not moved out of the duct and into any surrounding tissue. DCIS can be difficult to detect by physical examination and is usually discovered through a mammogram as very small specs of calcium known as microcalcifations.