Question

Once the desired separation of dyes has been achieved, turn off the power, disconnect the leads from the input, and resolve the top of the electrophoresis chamber. Carefully remove the easting tray and stride the gel into the plastic tray. Based on the direction of migration, migration distance, and the appearance of sour gel. what dye components were present in each of the unknown dye mixtures? which dye molecule traveled farthest through the gel? which traveled the shortest distance through the gel? what properties affect migration distance? what was the charge of the dye molecules that migrated toward the positive electrode and of the dye molecules that migrated toward the negative electrode? How do you know? Why is electrical current necessary for separating molecules by gel electrophoresis? Why is the porous matrix of agarose gels an essential component of molecule separation by gel electrophoresis?

Answer 1

1. Based on direction of migration, migration distance of gel, what dye components are present in your dye mixtures? INSUFFICIENT QUESTION, MORE INFORMATION NEEDED about the provided dye mixuture

2. Which dye molecule traveled farthest, which traveled shortest distance through the gel, what properties affect migration distance? INSUFFICIENT QUESTION, MORE INFORMATION NEEDED about the dye

(But Standard answer: Molecules with low molecular size will move faster while highmolecular weight molecules move slowly and hence run a short distance). Migration distance of a molecule is dependent on many factors. 1. Size of the molecule (Higher the size, lower is the run) 2 Net charge on the molecules (molecule is highly charged, it will move faster) and 3) Porosity of the matrix (dependent on the concentration of matrix used)

3. When a cell is charged, anode becomes the positive electrode (+) and cathode becomes negative electrode. Since anode is positive (which gives off electrons) negative dyes go towards anode. For example, proteins migrate towards anode because they have negative charge due to the presence of SDS.

On the other hand, positively charged molecules or dyes migrate towards cathode because it accepts electrons and hence is negatively charged. As we know that opposite charges attract, negative dyes migrate towards anode and positive dyes migrate towards anode.

4. Different molecules show the presence of different net surface charges. By applying an electric field, we will be able to separate them because it creates positive charge at one end and negative charge at the other end. For example, nucleic acids show net negative charge due to the presenc of phosphate bone, while for proteins, negative charge is imparted artificially by adding sodium dodecyl/lauryl sulfate (SDS). Hence both move towards positive electrode, anode after we apply electric field.

5. Agarose is a polysaccharide linear polymer and forms a gel once it is dissolved in a buffer and boiled and then kept for cooling. The melting and gelling temperatures depend on the type of agarose used. Porosity of the matrix depends on the concentration of agarose used in an electrophoresis gel. For example, 1% gel has large pores as compared to 2% gel. This porosity matrix helps in separating molecules based on molecular size. Smaller fragments move faster through the pores while large molecules move slowly as they are unable to move through the pores easily. Hence molecules with small size always travel fast and are observed at the bottom of the gel while high molecular weight molecules are observed on the top.