In the HIC some highly hydrophobic proteins may not even be eluted in the total absence of salt in such case water-miscible organic solvent such as propanol or ethylene glycol to the column buffer solution.

TLS Online TPP Program

#Id: 8070

#Unit 13. Methods in Biology

An optically active chiral compound will absorb the two directions of circularly polarized light by different amounts

TLS Online TPP Program

#Id: 8073

#Unit 13. Methods in Biology

In a chiral medium the molar absorptivity of LCP and RCP light are different so they will be absorbed by the medium in different amounts. 

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#Id: 8074

#Unit 13. Methods in Biology

Differential absorption of the two circularly polarized lights resulted in elliptically polarized light and CD is represented in terms of molar ellipticity(θ).

θ = 3298    ϵ

TLS Online TPP Program

#Id: 8075

#Unit 13. Methods in Biology

β-sheets shows a negative bands at 218nm and a positive one at 196nm.

Random coils has a positive band at 212nm and a negative one around 195nm.

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#Id: 8076

#Unit 13. Methods in Biology

CD can be used to estimate the structure of unknown proteins and monitor conformational changes due to temperature, mutations, heat, denaturants or binding interactions

TLS Online TPP Program

#Id: 8077

#Unit 13. Methods in Biology

CD spectra is used to

determine whether proteins are properly folded, 

estimate the fraction of the protein that is folded in either of the common secondary structures, and

monitor transitions between the folded and unfolded states.