TLS Online TPP Program

#Id: 4729


RNA gives absorbance at 595 nm in presence of Diphenylamine while gives directabsorbance at 540 nm.



#Unit 13. Methods in Biology #UV/visible #Part B Pointers
More Pointers
TLS Online TPP Program

#Id: 4720

#Unit 13. Methods in Biology

The absorption of UV light by nucleic acids arises from n!p* and p!p* transitions of the purine (adenine, guanine) and pyrimidine (cytosine, thymine, uracil) bases that occur between 260 nm and 275 nm. 

TLS Online TPP Program

#Id: 4721

#Unit 13. Methods in Biology

The absorption spectra of the bases in polymers are sensitive to pH and greatly influenced by electronic interactions between bases.




TLS Online TPP Program

#Id: 4722

#Unit 13. Methods in Biology

Biochemical samples are usually buffered aqueous solutions, which has two major advantages. Firstly, proteins and peptides are comfortable in water as a solvent, which is also the ‘native’ solvent. Secondly, in the wavelength interval of UV/Vis (700–200 nm) the water spectrum does not show any absorption bands and thus acts as a silent component of the sample





TLS Online TPP Program

#Id: 4723

#Unit 13. Methods in Biology

The absorption spectrum of a chromophore is only partly determined by its chemical structure. The environment also affects the observed spectrum, which mainly can
be described by three parameters:

protonation/deprotonation (pH, RedOx);
• solvent polarity (dielectric constant of the solvent); and
• orientation effects.

TLS Online TPP Program

#Id: 4724

#Unit 13. Methods in Biology

Concentration of protein can be analyzed by to method constructive and destructive method 


TLS Online TPP Program

#Id: 4725

#Unit 13. Methods in Biology

Destructive method uses Folin reagent, Biuret, BCA, Coomassie Brilliant Blue and give absorbance at 660, 540, 562, 595 nm of wavelength respectively.