MathBench > Visualization

Chopping up plasmids


Plasmids are pieces of DNA that contain recognition sites where restriction enzymes cut plasmid.

To separate and find out the length of fragments cut by restriction enzymes, scientist use a technique called gel electrophoresis. During gel electrophoresis, fragments with smaller size move faster while those with bigger size move slower.

A connected circle with 'x' number of recognition sites gets broken into 'x' pieces while a linear strand with 'x' number of recognition sites gets broken into 'x-1' pieces.

With different combinations of restriction enzymes in different lanes, and assuming that everything runs smoothly, there are no overlapping bands, and so on:

  1. The length totals for each lane must…
  2. The number of bands in a multi-enzyme lane (such as A+B) must …
  3. The longest fragment in a multi-enzyme lane cannot be …



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