control: plasmid + buffer + water
tube 1: plasmid + buffer + restriction enzyme A + water
tube 2: plasmid + buffer + restriction enzyme B + water
tube 3: plasmid + buffer + restriction enzyme A + B
purpose: determine length of fragments made by restriction enzymes.
question: why does control (plasmid + buffer + water) have to be the same volume?
thanks guys.
2006-09-27 18:12:08 · 2 answers · asked by Anonymous in Science & Mathematics ➔ Biology
Different volumes will place the specimens in different "area" sizes on the gel.
The idea is to be as consistant as possible.
2006-09-27 18:15:57 · answer #1 · answered by Richard 7 · 64⤊ 0⤋
In reality it probably wouldn't have much if any effect on the experiment.
Usually water is added to make the total volumes the same so the concentration of the other elements in the reaction are consistant across the board.
As a hypothetical to illustrate, in your experiment imagine that the buffer at high concentrations has a digestive effect on the plasmid (remember this is hypothetical and bear with me). the total volume of the test reactions are higher than the control with no water hence the concentration of the buffer is lower. this means that the control is not useful as a control as it is not behaving as the reaction would without the enzyme.
hope this isnt confusing you further but basically its all about concentrations.
2006-09-28 03:03:15 · answer #2 · answered by well_clever_i_am 3 · 0⤊ 0⤋