Gene expression can be quantified by measuring the accumulation of the protein products of genes. Immunoblotting and immunoprecipitation 

are the favorite ways of accomplishing this task.

TLS Online TPP Program

#Id: 2866

#Unit 13. Methods in Biology

A very weak absorption maximum of phenylalanine occurs at 257 nm, tyrosine and tryptophan dominate the typical protein spectrum with their absorption maxima at 274nm and 280 nm, respectively.

TLS Online TPP Program

#Id: 2867

#Unit 13. Methods in Biology

Cystine (Cys2) possesses a weak absorption maximum of similar strength as phenylalanine at 250 nm.

TLS Online TPP Program

#Id: 2868

#Unit 13. Methods in Biology

The absorption of UV light by nucleic acids arises from n ® p* and p ® p* transitions of the purine and pyrimidine bases that occur between 260nm and 275 nm.

TLS Online TPP Program

#Id: 2869

#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: 2870

#Unit 13. Methods in Biology

The characteristic absorption parameter for the sample is the extinction coefficient a, yielding the correlation I= I0e-ad.

TLS Online TPP Program

#Id: 2871

#Unit 13. Methods in Biology

The ratio T= I/I0 is called transmission.