Electrophoresis Quiz: Questions With Correct Solutions
Beta
Rationale: Low density lipoprotein (LDL) migrates in the beta region. Right
Ans - Which of the following bands is LDL most likely to be found in routine
SPE?
1.) Alpha one
2.) Alpha two
3.) Beta
4.) gamma
anions, anode
Rationale: The pH of the buffer will determine the state of ionization of the
charged groups of the constituent amino acids of proteins, and therefore their
electrical charges. A pH of 8.6 is usually chosen since at this pH the serum
proteins will have a negative charge (anions) and will move toward the anode
(pos. pole). Right Ans - At a pH of 8.6, proteins are ______ and migrate to the
_______.
1.) Anions, cathode
2.) Anions, anode
3.) Cations, cathode
4.) Cations, anode
Electroendosmosis
Rationale: In electroendosmosis, the medium acquires a negative charge, the
water molecules in close association with the medium become positively
charged and are attracted toward the cathode. The movement of water also
carries the separating proteins. The visible effect of this on serum protein
electrophoresis is that the slowest moving band, the gamma globulin, appears
separated towards the cathode side of the point of application. Right Ans -
Which of the following is responsible for the cathodal movement of gamma
globulins in serum protein electrophoresis at pH 8.6?
1.) Electroendosmosis
2.) Constant current
3.) Constant Voltage
4.) Low Buffer Ionic Strength
, Constant Voltage
Rationale: When a constant voltage is used, temperature increases, which
causes a decrease in resistance. According to Ohm's law, current must then
increase for the voltage to remain constant. As current increases, so does
migration of proteins. A change in migration rate during the electrophoresis
process is undesirable. Right Ans - What conditions listed below will
increase the migration of proteins toward the anode during electrophoresis?
1.) a more acidic pH of buffer
2.) high buffer ionic strength
3.) constant voltage conditions
4.) constant current conditions
The pH at which proteins have a neutral charge
Rationale: The mobility of a charged particle is a function of the magnitude of
the charge that, in turn, varies with pH. At their isoelectric point (pI), the net
charge is zero and their mobility would be zero.
At a pH < pI, they have a net positive charge due to the binding of protons and
migrate towards the cathode.
At a pH > pI, they have a net negative charge due to the loss of protons and
move towards the anode.
At pH = pI, they have no net charge (zero charge or neutral) Right Ans - The
isoelectric point is best defined by which of the following?
1.) the pH at which proteins have a positive charge
2.) the pH at which proteins have a negative charge
3.) the pH at which proteins will migrate toward the anode
4.) the pH at which proteins have a neutral charge
A sharp band between the beta and gamma globulin bands
Rationale: Fibrinogen: migrates between the beta and gamma globulins in a
distinct band - the major protein in fibrin clot formation. Right Ans - If a
serum sample has not completely clotted, fibrinogen appears as
1.) a sharp band between the beta and gamma globulin bands
2.) a band between the a1 and a2 bands
3.) a diffuse band seen at the point of application
4.) a broad band cathodal to the albumin band
It binds the transports copper in the plasma
Beta
Rationale: Low density lipoprotein (LDL) migrates in the beta region. Right
Ans - Which of the following bands is LDL most likely to be found in routine
SPE?
1.) Alpha one
2.) Alpha two
3.) Beta
4.) gamma
anions, anode
Rationale: The pH of the buffer will determine the state of ionization of the
charged groups of the constituent amino acids of proteins, and therefore their
electrical charges. A pH of 8.6 is usually chosen since at this pH the serum
proteins will have a negative charge (anions) and will move toward the anode
(pos. pole). Right Ans - At a pH of 8.6, proteins are ______ and migrate to the
_______.
1.) Anions, cathode
2.) Anions, anode
3.) Cations, cathode
4.) Cations, anode
Electroendosmosis
Rationale: In electroendosmosis, the medium acquires a negative charge, the
water molecules in close association with the medium become positively
charged and are attracted toward the cathode. The movement of water also
carries the separating proteins. The visible effect of this on serum protein
electrophoresis is that the slowest moving band, the gamma globulin, appears
separated towards the cathode side of the point of application. Right Ans -
Which of the following is responsible for the cathodal movement of gamma
globulins in serum protein electrophoresis at pH 8.6?
1.) Electroendosmosis
2.) Constant current
3.) Constant Voltage
4.) Low Buffer Ionic Strength
, Constant Voltage
Rationale: When a constant voltage is used, temperature increases, which
causes a decrease in resistance. According to Ohm's law, current must then
increase for the voltage to remain constant. As current increases, so does
migration of proteins. A change in migration rate during the electrophoresis
process is undesirable. Right Ans - What conditions listed below will
increase the migration of proteins toward the anode during electrophoresis?
1.) a more acidic pH of buffer
2.) high buffer ionic strength
3.) constant voltage conditions
4.) constant current conditions
The pH at which proteins have a neutral charge
Rationale: The mobility of a charged particle is a function of the magnitude of
the charge that, in turn, varies with pH. At their isoelectric point (pI), the net
charge is zero and their mobility would be zero.
At a pH < pI, they have a net positive charge due to the binding of protons and
migrate towards the cathode.
At a pH > pI, they have a net negative charge due to the loss of protons and
move towards the anode.
At pH = pI, they have no net charge (zero charge or neutral) Right Ans - The
isoelectric point is best defined by which of the following?
1.) the pH at which proteins have a positive charge
2.) the pH at which proteins have a negative charge
3.) the pH at which proteins will migrate toward the anode
4.) the pH at which proteins have a neutral charge
A sharp band between the beta and gamma globulin bands
Rationale: Fibrinogen: migrates between the beta and gamma globulins in a
distinct band - the major protein in fibrin clot formation. Right Ans - If a
serum sample has not completely clotted, fibrinogen appears as
1.) a sharp band between the beta and gamma globulin bands
2.) a band between the a1 and a2 bands
3.) a diffuse band seen at the point of application
4.) a broad band cathodal to the albumin band
It binds the transports copper in the plasma
