Gel Electrophoresis Study Guide – Questions And
Answers
When do scientists need to use gel electrophoresis? Right Ans - - when they
need go soft DNA strands into groups according to their lengths
What other types of molecules can be separated using gel electrophoresis?
Right Ans - - proteins
How do we make the DNA strands move through the gel? Right Ans - - the
gel is a filter, like a sponge, that sorts the DNA
- first, you put DNA samples in holes at one end of the gel
- the DNA is then pushed through the filter using electrophoresis, an electric
current
Which strands move through the gel more slowly? Right Ans - - the long
strands (the shorter strands move faster because they have less mass --> the
shorter strands end up farther away from the starting point than the longer
strands, which is how the different lengths sort themselves out)
Is it possible to see a single strand of DNA? Right Ans - - straining the DNA
makes groups of DNA visible to the naked eye, but not single strands
What is the purpose of adding a buffer when making the gel? Right Ans - -
to allow the electrical charges to flow through the gel
- to keep the gel from drying out
Why is it important to place the comb into one end of the gel before it cools?
Right Ans - - the notches in the gel hold the comb in place
What are wells used for? Right Ans - - to hold DNA samples
What will form as the gel cools? Right Ans - - tiny holes --> these are used
to hold the DNA
Answers
When do scientists need to use gel electrophoresis? Right Ans - - when they
need go soft DNA strands into groups according to their lengths
What other types of molecules can be separated using gel electrophoresis?
Right Ans - - proteins
How do we make the DNA strands move through the gel? Right Ans - - the
gel is a filter, like a sponge, that sorts the DNA
- first, you put DNA samples in holes at one end of the gel
- the DNA is then pushed through the filter using electrophoresis, an electric
current
Which strands move through the gel more slowly? Right Ans - - the long
strands (the shorter strands move faster because they have less mass --> the
shorter strands end up farther away from the starting point than the longer
strands, which is how the different lengths sort themselves out)
Is it possible to see a single strand of DNA? Right Ans - - straining the DNA
makes groups of DNA visible to the naked eye, but not single strands
What is the purpose of adding a buffer when making the gel? Right Ans - -
to allow the electrical charges to flow through the gel
- to keep the gel from drying out
Why is it important to place the comb into one end of the gel before it cools?
Right Ans - - the notches in the gel hold the comb in place
What are wells used for? Right Ans - - to hold DNA samples
What will form as the gel cools? Right Ans - - tiny holes --> these are used
to hold the DNA
