Gel Electrophoresis

Basic steps of gel electrophoresis technique: DNA is first cut using restriction enzymes, then loaded into wells of an agarose gel submerged in buffer.
When an electric current is applied, DNA migrates through the gel toward the positive end, because naturally- DNA has a negative charge. This technique separates DNA fragments by size, with smaller fragments moving faster through the agarose matrix. The agarose gel itself contains a DNA stain that fluoresces a bright yellow-green color when exposed to blue light, allowing for visualization of the DNA. The blue dye seen in the video indicates the migration rate of DNA, but the DNA bands are not visible without the stain. Therefore, the gel is placed under a UV transilluminator to reveal the fluorescent DNA bands.