Question

Why is agarose included in the gels you have been pouring?

How does a serological pipette differ from a micropipette? Include a comparison of the volumes you would pipet with each.

Answer 1

The agarose gel is a cross-linked matrix that is somewhat like a three-dimensional mesh or screen. The DNA molecules are pulled to the positive end by the current, but they encounter resistance from this agarose mesh. The smaller molecules are able to navigate the mesh faster than the larger one, so they make it further down the gel than the larger molecules. This is how agarose electrophoresis separates different DNA molecules according to their size. The gel is stained with ethidium bromide so you can visualize how these DNA molecules resolved into bands along the gel.

Micropipettes can have maximum volume of 1000 microlites or 1 millimitre

While serological pippette have volume from 1ml to 50 ml.