By mixing dried viral DNA with water, then adding different restriction enzymes, it can be cut into various lengths. Gel electrophoresis is then used to separate the pieces.
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After rehydrating the DNA it is added to the tubes of enzymes and incubated for 45 minutes. Meanwhile agarose gel is poured into trays and allowed to set. |
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The DNA has a loading dye added before putting it into the wells in the gel. After running an electric current through it for seven hours the fragments of DNA are separated. |
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Results Example
Year 13 Biology students' prep.
The table below gives the sizes
of the major DNA fragments produced by the enzymes you used. The unit is base pairs. EcoRI HindIII BamHI 21 226 23 130 16 841 5 643 & 5 804 & 4 878 9 416 6 527 & 5 626 & 5 505 3 530 6 557 4 361 2 125 The control (uncut DNA) was put
in the left hand well. All the samples with restriction enzymes added had some
uncut DNA remaining so the first band in each case contains this. It has a
little over
25 000 base pairs. Use this table to identify which restriction enzyme was used to cut
the DNA in each of the other three wells in the example above. Print out or copy the photo of the
results, draw around each band, and label it showing the size of the DNA
fragment or fragments it contains. Indicate the restriction enzyme used in each
case.
