Gel Electrophoresis

Gel electrophoresis is a method used to separate DNA, RNA, or proteins based on size. It allows scientists to analyze the results of experiments like PCR or restriction digests.

How it works:

DNA samples are loaded into wells in a gel, usually made of agarose. The gel is placed in a buffer solution and connected to an electric current. Because DNA is negatively charged, it moves toward the positive electrode. Smaller DNA fragments move more easily through the gel matrix and travel farther than larger fragments.

To see the DNA, the gel is stained with a dye that binds to DNA and fluoresces under UV light. A DNA ladder, which contains fragments of known sizes, is run alongside the samples to help estimate the size of unknown fragments.

Applications:

• Visualizing PCR products

• Checking for successful DNA digestion

• Analyzing DNA fingerprints in forensics

• Estimating the size of DNA fragments

How to interpret data:

The results appear as bands in the gel. Each band represents DNA fragments of a specific size. By comparing sample bands to the DNA ladder, you can estimate the size of the fragments. Bands at the same spot are the same size. The presence, absence, or pattern of bands can indicate whether the target DNA is present or how it was altered in an experiment. Larger bands signify that there is more DNA, while smaller bands signify that there is less DNA.