DNA fingerprinting is a process that is done to determine the genetic makeup of a person. It is done by collecting samples of sweat, blood, saliva, hair, or other bodily fluids. This is done in forensic studies to determine blood relationships between people, to study diseases, and much more. Gel electrophoresis is a laboratory technique that is used to analyze fragments of DNA, RNA, and proteins based on the size and the charge they carry. The fragments to be analyzed are placed in a gel that has small pores.
The fragments are pushed by an electric field. The separate fragments will travel across the gel with speed inversely proportional to their length. This means shorter fragments will travel farther than longer fragments. By default, DNA and RNA are negatively charged, so if fragments of DNA and RNA are being processed, it will move towards the positive side.
DNA profiling and gel electrophoresis are actually very different things. DNA profiling is where scientists can take your DNA from either blood, sweat, saliva, other bodily fluids or hair and use it to either compare your DNA with someone else's, to study diseases or to even convict you of a crime if you leave behind some of your DNA that they can test.
This is done by collecting a sample from you, chemically breaking it down and then dissolving it in water. Gel electrophoresis is used to organize the DNA by size. The molecules are pushed through a gel that has small holes. This will allow smaller molecules to go through it while leaving the larger ones behind.