Cryptic mutants” of lac operon make b-galactosidase but still could not grow on lactose means they are essentially Y-

TLS Online TPP Program

#Id: 2809

#Unit 13. Methods in Biology

In RPLC the stationary phase is non-polar and the mobile phase relatively polar, hence the name reversed-phase

TLS Online TPP Program

#Id: 2810

#Unit 13. Methods in Biology

In RPLC stationary phase most commonly used is in the bonded-phase form, in which alkylsilane groups are chemically attached to silica. Butyl (C4), octyl (C8) and octadecyl (C18) silane groups are most commonly used.

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#Id: 2811

#Unit 13. Methods in Biology

In RPLC mobile phase is commonly water or aqueous buffers, methanol, acetonitrile or tetrahydrofuran, or mixtures of them.

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#Id: 2812

#Unit 13. Methods in Biology

 In RPLC the organic solvent is referred to as an organic modifier.

TLS Online TPP Program

#Id: 2813

#Unit 13. Methods in Biology

Reversed-phase liquid chromatography differs from most other forms of chromatography in that the stationary phase is essentially inert and only non-polar (hydrophobic) interactions are possible with analytes.

TLS Online TPP Program

#Id: 2814

#Unit 13. Methods in Biology

Proteins differ in the amount of hydrophobic amino acids that are present on their surface. This difference can be exploited in salt fractionation but can also be used in a higher resolution method using hydrophobic interaction chromatography (HIC).