1. What did you see? What colors were actually in
the black ink?
2. Which colors were carried furthest? (the
lighter colors) Which remained lowest? (the
3. Which color is the lightest in weight? (those
lightest in color) The heaviest in weight? (the
4. What pattern was there to the change?
5. What is happening when the colors move up the
paper? (the molecules of color are being dissolved
by the water and carried with the water up the paper)
6. What causes the colors to separate? (the
different colors have different affinities for clinging
to the paper, and those that cling hardest to the
cellulose in the paper will stop first, and those
that cling the weakest will travel further up the
filter paper before stopping)
7. Predict what might happen with different colors.
Try it again. Do you get the same results?
1. This is the same principle used in gel electrophoresis,
which is a type of DNA fingerprinting. A DNA sample
is placed in a gel bed, current is run through it,
and the DNA fragments move across the bed, ending
up in different spots. Identical samples of DNA
will always have the same results. The banding seen
in these results is used to compare DNA samples.