Introduction to Electrophoresis
40 Questions
0 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the primary purpose of electrophoresis?

  • To enhance the solubility of macromolecules
  • To transport particles through a solvent using an electric field (correct)
  • To apply high temperatures to separate compounds
  • To mix different solvents for analysis

    • Which of the following best describes the term 'phoresis' in electrophoresis?

  • Charge
  • Identification
  • Movement
  • Separation (correct)

    • What factor affects the movement of ions during electrophoresis?

  • Electric field strength only
  • Temperature and atmospheric pressure
  • Weight, molecular shape, and size (correct)
  • Concentration of the solvent

    • What is the primary force opposing the electrophoretic migration of ions in solution?

    <p>Frictional force</p> Signup and view all the answers

    In electrophoresis, which type of macromolecule is primarily analyzed?

    <p>Proteins</p> Signup and view all the answers

    In which type of electrophoresis are charged molecules separated without a supporting medium?

    <p>Moving boundary electrophoresis</p> Signup and view all the answers

    How does the charge of macromolecules affect their movement in electrophoresis?

    <p>They travel towards the electrode with opposite charge</p> Signup and view all the answers

    What is one of the advantages of using electrophoresis for analysis?

    <p>It can separate samples quantitatively</p> Signup and view all the answers

    Which factor does NOT impact the frictional coefficient of an ion during electrophoresis?

    <p>Electric field strength</p> Signup and view all the answers

    What disadvantage is associated with moving boundary electrophoresis?

    <p>Mixing and overlapping of sample components</p> Signup and view all the answers

    What does F electric represent in the electrophoresis theory?

    <p>Electric force on an ion</p> Signup and view all the answers

    How are positively charged molecules affected by an electric field during electrophoresis?

    <p>They move towards the anode</p> Signup and view all the answers

    Which form of electrophoresis involves the physical arrangement of samples on paper or gel?

    <p>Zone electrophoresis</p> Signup and view all the answers

    What is the purpose of the refractometer in moving boundary electrophoresis?

    <p>To measure changes in refractive index</p> Signup and view all the answers

    What is primarily separated during electrophoresis?

    <p>Molecules and ions</p> Signup and view all the answers

    What fundamental principle underlies the process of electrophoresis?

    <p>Electrokinetic motion</p> Signup and view all the answers

    What is a major limitation of paper electrophoresis?

    <p>Lack of sensitivity</p> Signup and view all the answers

    Why is cellulose acetate preferred over paper for electrophoresis?

    <p>Higher resolution at low voltage</p> Signup and view all the answers

    Which of the following statements about gel electrophoresis is true?

    <p>It utilizes a porous gel matrix for molecule separation.</p> Signup and view all the answers

    What is the most common form of gel electrophoresis?

    <p>Horizontal electrophoresis</p> Signup and view all the answers

    What happens to negatively charged molecules during electrophoresis?

    <p>They attract toward the positive end.</p> Signup and view all the answers

    What is added to the agarose solution during the casting of horizontal gel electrophoresis?

    <p>Electrophoresis buffer</p> Signup and view all the answers

    What type of molecules tends to lag behind in gel electrophoresis?

    <p>Heavy molecules</p> Signup and view all the answers

    What modification happens to the hydroxyl groups in cellulose acetate to reduce its adsorption capacity?

    <p>They are converted to acetate groups.</p> Signup and view all the answers

    What is a primary advantage of using supporting media in zone electrophoresis?

    <p>It minimizes mixing of the sample.</p> Signup and view all the answers

    Which of the following is NOT a method of electrophoresis mentioned?

    <p>Thin layer electrophoresis</p> Signup and view all the answers

    What type of molecules is paper electrophoresis primarily useful for separating?

    <p>Small charged molecules</p> Signup and view all the answers

    What happens to the spots during paper electrophoresis?

    <p>They migrate according to their charges.</p> Signup and view all the answers

    Which characteristic of paper electrophoresis makes it easier compared to gel electrophoresis?

    <p>It does not involve matrix preparation.</p> Signup and view all the answers

    In what type of applications is paper electrophoresis utilized?

    <p>Study of sickle cell disease and hemoglobin abnormalities.</p> Signup and view all the answers

    What electrophoresis method is best exemplified by gel electrophoresis?

    <p>Zone electrophoresis</p> Signup and view all the answers

    Why is the application of high voltage crucial in paper electrophoresis?

    <p>It minimizes diffusion and enhances resolution.</p> Signup and view all the answers

    What is the purpose of adding Bromophenol blue in gel electrophoresis?

    <p>To act as a visual tracking dye</p> Signup and view all the answers

    Which component is essential for the solidification of the resolving gel in SDS-PAGE?

    <p>Polyacrylamide</p> Signup and view all the answers

    During capillary electrophoresis, what mechanism is primarily used to inject the sample through the capillary tube?

    <p>Electrokinetic energy</p> Signup and view all the answers

    What is the purpose of placing a ladder in electrophoresis?

    <p>To determine the migration distance</p> Signup and view all the answers

    What happens to the gel after the completion of SDS-PAGE electrophoresis?

    <p>It is rinsed with deionized water</p> Signup and view all the answers

    What is the main reason for using an electrolytic solution in capillary electrophoresis?

    <p>To create an electric field for migration</p> Signup and view all the answers

    In the process of agarose gel electrophoresis, what is the function of the gel loading buffer?

    <p>To allow samples to be visualized during loading</p> Signup and view all the answers

    What type of bands does the Coomassie blue stain reveal in SDS-PAGE?

    <p>Invisible protein bands</p> Signup and view all the answers

    Study Notes

    Introduction to Electrophoresis

    • Electrophoresis is the movement of charged particles through a solvent under the influence of an electric field.
    • Most polymers containing macromolecules are electrically charged and thus move in an electric field.
    • Electrophoresis is useful for identifying and determining the structure of large molecules.

    Definition of Electrophoresis

    • "Electro" refers to electricity.
    • "Phoresis" refers to separation.
    • Electrophoresis separates compounds capable of acquiring an electric charge in conducting electrodes.
    • Electrophoresis is the migration of a charged particle through a solution in an external electric field.
    • Ions suspended between electrodes migrate towards oppositely charged electrodes.

    Theory of Electrophoresis

    • Ion mobility depends on the frictional coefficient.
    • The frictional coefficient depends on factors like molecular weight, shape, and size of the molecules.
    • The law of electrostatics states that the electric force (F) on an ion is equal to the charge (q) of the ion multiplied by the electric field strength (E).
    • Felectric = qE
    • The electrophoretic migration through the solution is opposed by a frictional force.
    • Ffriction = Vf Where V is the velocity and f is the frictional coefficient.
    • The frictional coefficient measures the drag exerted by the solution and depends on the ion's size, shape, state, and solution viscosity.

    Working Principle of Electrophoresis

    • Electrophoresis separates molecules, ions, or colloidal particles suspended within a matrix under the influence of an electric field.
    • Positively charged molecules migrate towards the anode, while negatively charged molecules migrate towards the cathode.
    • Electrophoresis is an electrokinetic phenomenon where molecule movement is driven by an electric field.

    Types of Electrophoresis

    • Moving Boundary Electrophoresis:

      • Separates components in a solution without a supporting medium.
      • Electrophoresis is carried out in a U-shaped tube with platinum electrodes.
      • Samples are dissolved in buffer and migrate to their respective opposing charge electrodes.
      • Analyte migration is monitored by refractive index change detected by a refractometer placed at the ends of the U-tube.
      • The resolution is relatively low due to mixing of sample components.

    • Zone Electrophoresis:

      • Involves use of an inert polymeric support medium between electrodes.
      • Supporting media include paper, starch, agar, or polyacrylamide ("gel").
      • The media immobilizes molecules post-electrophoresis, aiding analysis and purification.
      • Significantly improves separation resolution compared to moving boundary electrophoresis.

    Methods of Zone Electrophoresis

    • Paper Electrophoresis:

      • Uses a strip of filter paper saturated with buffer.
      • Samples are spotted on the paper and subjected to a high voltage field, causing separation based on charge.
      • Separated components are visualized using staining.

    • Cellulose Acetate Electrophoresis:

      • Employs cellulose acetate membrane which has lower adsorption capacity compared to paper.
      • Improved resolution at lower voltage compared to paper electrophoresis.

    • Gel Electrophoresis:

      • Uses gel matrices as a support medium.
      • The gel's porous structure separates components based on size and charge.
      • Popular methods include agarose gel electrophoresis (for DNA/RNA) and SDS-PAGE (for proteins).

    Factors Affecting Electrophoresis

    • Electric Field Strength:

      • Higher voltage usually corresponds with faster separation.

    • Sample Characteristics:

      • Charge, size, shape, and binding strength of molecules influence migration rate.

    • Buffer:

      • Ionic strength and pH characteristics impact molecular charges and migration.

    • Supporting Medium:

      • Porosity, structure, and composition of medium affect the separation process.

    Applications

    • Electrophoresis is a valuable tool in various fields, including clinical diagnostics, forensics, molecular biology, and food analysis, to separate proteins, DNA, RNA, and various other molecules.

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Related Documents

    Electrophoresis PDF

    Description

    This quiz covers the basic concepts of electrophoresis, including its definition, theory, and significance in separating charged particles. Understanding how electric fields influence the movement of macromolecules is crucial for identifying these compounds. Test your knowledge about the principles and applications of electrophoresis.

    More Like This

    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser