TABLE OF CONTENTS Autoradiography is a well suited technique used as a standard and powerful analysis tool in biological, biochemical, medical and biophysical fields. Applications of autoradiography ranges from morphological studies on biological samples and biomolecular studies (as analysis of dot blots, electrophoresis, protein/amminoacid uptake and localization) to dynamic studies of biological mechanisms. It consists in mapping the distribution of a radioactive marker (the most common used are 3H, 14C, 35S, 32P) in a radiolabelled sample, and takes advantage of the fact that animals and plants cannot distinguish between stable and radioactive isotopes of the same elements in their physiological reactions.
"Blots" [1] are membranes such as nitrocellulose or coated nylon to which nucleic acids have been permanently bound. Blot hybridizations with specific nucleic acid probes provide critical information regarding gene expression and genome structure. The most common blot applications used in modern laboratories are Northern blots, Southern blots and dot/slot blots. Regardless of the type of blot, the principles of probe synthesis, hybridization, washing and detection are the same.
Southern blotting [2] involves separating DNA fragments on agarose gels then denaturing them in situ. Fragments are then transferred to a nitrocellulose or nylon membrane where they are immobilized. After prehybridization to reduce non-specific hybridization with the probe, the membrane is hybridized with the desired labeled nucleic acid probe. The membrane is subsequently washed to remove unbound and weakly binding probe, and is then...
