Gel Electrophoresis CPAC
Aim: Using gel electrophoresis to separate DNA fragments of different lengths
Variables:
Independent- The contents of the sample (DNA and different enzymes including pre-digested enzymes
for ‘Scene of the crime’)
Dependent- The sizes of the DNA strands (fragments) under UV light
Control Variable How it’s controlled Why
Amount of buffer solution By using micropipettes to
measure out 10μl for each
sample.
Scientific Background
Figure 1: A diagram showing the apparatus used for gel electrophoresis (2)
Method:
1. Obtain the DNA sample by mixing each sample with endonuclease enzymes in 4 test tubes.
2. Use a micropipette to add 10μl of the buffer solution into four different test tubes.
3. Add the following to each test tube:
- Test tube 1- DNA sample 1 with Enzyme 1
Test tube 2- DNA sample 1 and enzyme 2
Test tube 3- DNA sample 2 with Enzyme 1
Test tube 4- DNA sample 2 with Enzyme 2
Aim: Using gel electrophoresis to separate DNA fragments of different lengths
Variables:
Independent- The contents of the sample (DNA and different enzymes including pre-digested enzymes
for ‘Scene of the crime’)
Dependent- The sizes of the DNA strands (fragments) under UV light
Control Variable How it’s controlled Why
Amount of buffer solution By using micropipettes to
measure out 10μl for each
sample.
Scientific Background
Figure 1: A diagram showing the apparatus used for gel electrophoresis (2)
Method:
1. Obtain the DNA sample by mixing each sample with endonuclease enzymes in 4 test tubes.
2. Use a micropipette to add 10μl of the buffer solution into four different test tubes.
3. Add the following to each test tube:
- Test tube 1- DNA sample 1 with Enzyme 1
Test tube 2- DNA sample 1 and enzyme 2
Test tube 3- DNA sample 2 with Enzyme 1
Test tube 4- DNA sample 2 with Enzyme 2
