What is the purpose of thecomb?

A comb is a tool consisting of a shaft that holds a row of teeth for pulling through the hair to clean, untangle, or style it. Combs have been used since prehistoric times, having been discovered in very refined forms from settlements dating back to 5,000 years ago in Persia.

1. What is the purpose of using a comb in the DNA gel?
2. Why is the comb placed in the center for this electrophoresis experiment?
3. Where do you place the comb in gel electrophoresis?
4. Why is a comb placed in the melted gel?
5. What is the purpose of the power supply in gel electrophoresis?
6. How does a gel electrophoresis chamber function?
7. What is an electrophoresis chamber?
8. Why is it important to pour slowly and avoid air bubbles?
9. What do the bubbles on the electrodes tell you?
10. How does gel electrophoresis separate molecules?
11. How does gel electrophoresis help analyzing samples of DNA?
12. How is gel electrophoresis used in forensics?
13. What is the purpose of the comb quizlet?
14. What does it mean that there is only one band in a lane?
15. What would happen if the gel was run for too long?

What is the purpose of using a comb in the DNA gel?

The purpose of the comb in gel electrophoresis is to create wells to hold the samples. Before gel electrophoresis, scientists need to cast the gel. While the gel is still liquid, a comb is set at the top of the gel. This creates wells, or holes, that will hold the samples during electrophoresis.

Why is the comb placed in the center for this electrophoresis experiment?

The comb is in the center of the gel since the dyes used have either positive or negative charges and can therefore migrate in different directions.

Where do you place the comb in gel electrophoresis?

The comb is placed in slots on the side of the casting tray. It is put in the slots BEFORE the hot, melted gel is poured. After the gel solidifies, the comb is taken out. The "teeth" of the comb leave small holes in the gel that we call "wells."

Why is a comb placed in the melted gel?

The molten gel is then poured into a gel casting tray and a “comb” is placed at one end to make wells for the sample to be pipetted into. Once the gel has cooled and solidified (it will now be opaque rather than clear) the comb is removed. Many people now use pre-made gels.

What is the purpose of the power supply in gel electrophoresis?

Power Supply

Power supplies for electrophoresis are used to create the electrical current to power DNA/RNA separations, PAGE electrophoresis and transferring to membrane. The voltage determines the scope of function with 300V strong enough for running gels while 250V is needed to perform transfers.

How does a gel electrophoresis chamber function?

Electrophoresis is a process that enables the sorting of molecules based on size. ... The gel is placed in an electrophoresis chamber, which is then connected to a power source. When the electric field is applied, the larger molecules move more slowly through the gel while the smaller molecules move faster.

What is an electrophoresis chamber?

Invitrogen electrophoresis chamber systems are tanks composed of an upper (anode) and lower (cathode) buffer chamber connected by platinum wire electrodes. ... Applying an electrical field across the buffer chambers forces the migration of proteins into and through the polyacrylamide gel.

Why is it important to pour slowly and avoid air bubbles?

'Pro-Tip': Pour slowly to avoid bubbles which will disrupt the gel. Any bubbles can be pushed away from the well comb or towards the sides/edges of the gel with a pipette tip.

What do the bubbles on the electrodes tell you?

Beneficial Bubbles

When running agarose or polyacrylamide gels, bubbles mean the electrodes are connected, plugged in, and that current is flowing.

How does gel electrophoresis separate molecules?

In gel electrophoresis, the molecules to be separated are pushed by an electrical field through a gel that contains small pores. ... This means that a small DNA molecule will travel a greater distance through the gel than will a larger DNA molecule.

How does gel electrophoresis help analyzing samples of DNA?

How does gel electrophoresis help when analyzing samples of DNA? It separates DNA fragments by length. ... You perform PCR for two different STRs at the same time and then load the reaction onto a gel.

How is gel electrophoresis used in forensics?

Gel electrophoresis is used to create DNA fingerprints from crime scene and suspect samples. A match between samples suggests which suspect committed the crime.

What is the purpose of the comb quizlet?

The purpose of the comb is to provide wells in which the DNA samples will be placed in.

What does it mean that there is only one band in a lane?

Digested DNA fragment may have a single band at almost similar size with your PCR product. This is your target size, and the band in this digested DNA fragment is the one you want to excise. At the bottom of the PCR product lane, you may see a faint band indicating small molecules.

What would happen if the gel was run for too long?

What would happen if the gel was run for too long? The sample bands would move too far and leave the bottom of the gel.