Question

Describe the methods for visualizing DNA molecules after separation.

Short answer

The separated DNA molecules can be visualized using UV light after staining with an appropriate dye.

Step-by-step solution

Separation of DNA molecules

The Agarose gel electrophoresis is used in separating DNA fragments of different sizes. As DNA molecules possess negative charges, they are easily pulled through the gel by an electric field. The DNA molecules with fewer base pairs move more quickly through the gel than larger DNA molecules. Under the electric field, DNA molecules move toward anodes due to their negative charge. The conventional technique is used to separate bonds cut from the gel and extracted using. The eluted DNA fragments are analyzed and purified, later used in recombinant DNA.

Visualization of DNA molecules after separation

UV rays are used to visualize the DNA molecules after separation. For the radioactive probe, an autoradiogram is made by placing the nitrocellulose over a sheet of X-ray film. Other procedures, such as a position-sensitive radiation detector, can be used. For a fluorescent probe, an imaging instrument is used to produce a digital photograph