Chromatography

In Chromatography the retardation factor R_f are used for identification of components. A high  R_f and a low R_t (retention time) mean the component has a 

• greater affinity to the stationary phase in both TLC and HPLC.
• greater affinity to the stationary phase in TLC but a greater affinity for the mobile phase in HPLC
• greater affinity to the mobile phase in TLC but a greater affininty for the stationary phase in HPLC
• greater affinity to the mobile phase in  both TLC  and HPLC

The mobile phase in paper chromatography is typically a

• plasma
• solid
• gas
• liquid

The substance in the mixture that has the greatest affinity for the mobile phase will travel

• fastest
• slowest

The retention factor is used

• to zero the chromatography scale
• to identify unknown compounds in a sample
• to retain solvent
• as a starting tool for chromatography

A characteristic feature of any form of chromatography is the ...

• calculation of an Rf value for the molecules separated.

• use of an inert carrier gas.

• use of a mobile and a stationary phase.

• use of molecules that are soluble in water.

Thin layer chromatography is

• partition chromatography

• electrical mobility of ionic species

• adsorption chromatography

• none of the above

Ion-Exchange chromatography:

• separate and analyze compounds that can be vaporized without decomposition

• Also known as Liquid-Solid Chromatography

• Materials used are either cation or anion resins

• Separation based on partition coefficient between 2 immiscible liquids

What type of chromatography is depicted by the illustration?

• Gel Filtration Chromatography

• Column Chromatography

• HPLC

• Thin Layer Chromatography

Which of the following methods could be used to check the molecular weight of your purified protein?

• SDS-PAGE

• Mass Spectrometry

• Analytical SEC

• All of above

To elute target proteins from an affinity chromatography matrix, which of the following conditions would be the most appropriate?

• Low salt concentrations

• High salt concentrations

• Adding a soluble ligand which competes with the affinity tagged protein for binding to the column

• Just keep washing buffer through the column, isocratic elution