Question

pre - lab questions/lab: gel electrophoresis

1. shorter strands of dna travel _, farther on the agarose gel than do larger strands.
2. what is the direction of the current under the application of an electric field? (choose one: positive to negative or negative to positive)
3. what is the purpose of the wells?
4. what would happen if di water is used instead of tae buffer?
5. what is the charge of the dna?
6. what colors form the grape kool - aid? (tip: use the information from the kool - aid label)
7. what color form the orange kool - aid? (tip: use the information from the kool - aid label)

Explanation:

:

1. Faster
2. Positive to negative
3. To hold the DNA samples.
4. DNA would not migrate properly as DI water lacks the ions needed for conductivity and proper buffering.
5. Negative
6. Answers may vary based on the Kool - Aid label. For example, it may contain red and blue dyes to form grape color.
7. Answers may vary based on the Kool - Aid label. For example, it may contain red and yellow dyes to form orange color.

1. Smaller DNA fragments move more quickly through the gel matrix.
2. By convention, current flows from positive to negative in an electric field.
3. Wells are designed to place DNA samples at the starting point of the gel.
4. TAE buffer provides ions for conductivity and maintains pH for proper DNA migration.
5. DNA has a negative charge due to the phosphate groups in its backbone.

6 - 7. Kool - Aid colors are made from combinations of food dyes as indicated on the label.

Answer:

1. Smaller DNA fragments move more quickly through the gel matrix.
2. By convention, current flows from positive to negative in an electric field.
3. Wells are designed to place DNA samples at the starting point of the gel.
4. TAE buffer provides ions for conductivity and maintains pH for proper DNA migration.
5. DNA has a negative charge due to the phosphate groups in its backbone.

6 - 7. Kool - Aid colors are made from combinations of food dyes as indicated on the label.