3-5.7.2 Non-isotopic labeling:

Non-isotopic labeling systems involve the use of nonradioactive probes. These methods are developed recently as compared to radioisotope labeling methods, but are finding wide variety of applications in different ways. Two types of non-radioactive labeling are conducted: direct and indirect.

3-5.7 .2.1 Directnon-isotopic labeling, where a nucleotide containing label such as Fluorescein, Texas Red, Rhodamine that will be detected when incorporated with the help of spacer molecule. These modified nucleotides having tag, fluoresce when excited by light of certain wavelength.

Fig 3-5.7.2.1 An example of fluorescein conjugated dUTP . The fluorescein group is linked to the 5′ carbon atom of the uridine by a spacer group. Similarly, Rhodamine can also be used in place of fluorescein.