Tag: electrophoresis

Questions Related to electrophoresis

A mixture containing DNA fragments, A, B, C and D, with molecular weights of $A + B =C, A>B$ and $D>C$, was subjected to agarose gel electrophoresis. The positions of these fragments from cathode to anoe sides of the gel would be

  1. $D, C, A, B$

  2. $A, B, C, D$

  3. $C, B, A, D$

  4. $B, A, D, C$


Correct Option: A
Explanation:

Gel electrophoresis is the techniques by which negatively charged DNA fragments separate according to their molecular mass and the principle says that lighter goes the maximum distance that means heavy DNA stops first as D is heavier it separates first while B at last.

So the correct option is 'D,C,A,B'.

Gel electrophoresis is a

  1. Technique of separation of charged molecules under the influence of magnetic field

  2. Technique of incorporation of DNA molecules into the cell through transient pores made due to electrical impulses

  3. Technique of separation of DNA fragments through the pores of agarose gel under the influence of electric field

  4. Technique of separation and purification of gene products


Correct Option: C
Explanation:
Electrophoresis is a technique of separation of molecules such as DNA, RNA or protein, under the influence of an electrical field, so that they migrate in the direction of electrode bearing the opposite charge, viz. positively charged molecules move towards cathode (-ve electrode) and negatively charged molecules travel towards anode (+ve electrode) through a medium/matrix. Since DNA fragments are negatively charged molecules, they can be separated by allowing them to move towards the anode (+ve electrode) under an electric field through a matrix of agarose gel.
So, the correct answer is 'Technique of separation of DNA fragments through the pores of agarose gel under the influence of electric field'.

Gel electrophoresis is a

  1. Technique of separation of charged molecules under the influence of magnetic field

  2. Technique of incorporation of DNA molecules Into the cell through transient pore made due to electrical impulses

  3. Technique of separation and isolation of DNA fragments through the pores of agarose

  4. Technique of separation and purification of gene products.


Correct Option: A
Explanation:

Electrophoresis is defined as a technique of separation of the charged molecules of the substance in a solution, by subjecting them to an electric field. The technique helps to determine the number, amount and the mobility of the components in a given sample or separate them. It is also used to obtain information about the electrical double layer, surrounding the particles. Differential migration of the charged molecules in the presence of the electric field is the main principle of electrophoresis. The resolving power of electrophoresis was greatly improved by the introduction of a technique called zone technique. The zone electrophoresis performed by using gel is referred to as gel electrophoresis. 

So the correct option is 'technique of separation of charged molecules under the influence of magnetic field'.

DNA or RNA segment tagged with a radioactive molecule is called

  1. Probe

  2. Clone

  3. Plasmid

  4. Vector


Correct Option: A

Which technique is used in separating fragments of DNA ______________.

  1. Eastern blotting

  2. Western blotting

  3. Northern blotting

  4. Southern blotting


Correct Option: D

The universal DNA probe is made up of repeated tandems of?

  1. TATA

  2. GATA

  3. CACA

  4. ATGA


Correct Option: A

After the biosynthetic phase, the product is separated and purified by the process called as:

  1. Agarose gel electrophoresis

  2. PCR

  3. Downstream processing

  4. Insertional inactivation


Correct Option: C
Explanation:
After the biasynthetic, the product is seprated and parified by the process called doren stream processing. It involves $5$ stages.
$(1)$ solid- liquid sepretion
$(2)$ Retrase of intractual products
$(3)$ concentration
$(4)$ Purification by chronatography
$(5)$ Formulation
So, the correct answer is $[C]$ Downstrain processing.

What must be done before placing DNA into the electrophoretic chamber?

  1. It must be ground up with mortar and pestle

  2. It must be cut by restricition endonucleases

  3. It must be treated with RNAase

  4. None of these


Correct Option: B
Explanation:

Answer is option B i.e. "It must be cut by restriction endonucleases"
Electrophoresis is a method for separation of macro-molecules like DNA. Preparing the DNA for electrophoresis is an important step. DNA is "digested" or cut by restriction enzymes before being run on a gel so that DNA can be separated based on DNA size, fragment and length.

Purified DNA ultimately precipitate out after the addition of chilled ethanol. This DNA that separate out can be removed by _____________.

  1. Electrophoresis

  2. Downstream processing

  3. PCR

  4. Spooling


Correct Option: D
Explanation:

Answer is option D i.e. "Spooling"
At the last step of DNA extraction, purified DNA precipitates out after the addition of chilled ethanol. This DNA appears as collection of fine threads in the suspension which can be spool over the glass rod, this method is called as DNA spooling.

Agarose which is extracted from sea weeds is most widely used in

  1. Gel electrophoresis

  2. Spectrophotometry

  3. Tissue culture

  4. PCR


Correct Option: A
Explanation:

Agarose is the supporting structure in the cell walls of certain species of algae and which is released on boiling. Agarose is a polysaccharide polymer extracted from seaweed. Slabs of agarose gels are used for electrophoresis.
Thus, the correct answer is option A.