Fluorescence In Situ Hybridization

Abstract

Many interesting new hypotheses about neural stem cells are now being tested. For example, understanding the potential of stem cells from nonneuronal tissue types to differentiate into neural tissue is of great interest. Definitive proof of some of these hypotheses requires overcoming current technical limitations and difficulties. One of the technical challenges of research involving neural stem cells is identification of transplanted cells in situ. Unequivocal identification of transplanted cells after integration into host brain tissue can be extremely difficult. Genes inserted into donor cells to code for marker proteins may be downregulated over time, or may be downregulated after stem cells differentiate into mature neural cells. Cells prelabelled with Bromodeoxyuridine (BrdU) or a tracer dye may continue to divide, thus diluting the label until daughter cells carry so little label that it is below detectable levels. Cross-species transplantation (mouse into rat or human into rodent, for example) requires identification of donor cells by antibodies that are absolutely species specific, which is sometimes difficult to achieve.