TLS Online TPP Program

#Id: 6888


Regardless of how many X chromosomes are present, all but one will be inactivated. 
In normal females there are of course two X chromosomes, but in rare cases where nondisjunction has generated a 3X or greater genotype, only one X chromosome remains active



#Unit 3. Fundamental Processes #Eukaryotic Chromosome Architecture #Part B Pointers
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TLS Online TPP Program

#Id: 2474

#Unit 13. Methods in Biology

In ITP, the separation is carried out in a discontinuous buffer system. The ionized sample migrates between a leading electrolyte with a high mobility and a terminating – sometimes called trailing – ion with a low mobility, all of them migrating with the same speed.




TLS Online TPP Program

#Id: 2475

#Unit 13. Methods in Biology

IEF takes place in a pH gradient and can only be used for amphoteric substances such as peptides and proteins. The charged molecules move toward the anode or the cathode until they reach a position in the pH gradient where their net charges are zero. This pH value is the “isoelectric point” (pI) of the substance.


TLS Online TPP Program

#Id: 2476

#Unit 13. Methods in Biology

Agarose is one of the components of agar, which is a mixture of polysaccharides isolated from certain seaweeds and usually used at concentrations of between 1% and 3% in labs. 


TLS Online TPP Program

#Id: 2477

#Unit 13. Methods in Biology

Agarose gels are formed  by suspending dry agarose in aqueous buffer, then boiling the mixture until a clear solution forms. 



TLS Online TPP Program

#Id: 2478

#Unit 13. Methods in Biology

The most commonly used buffer for separating DNA is TRIS-acetate containing EDTA ( TAE) with a typical pH of 8.3 and used to dissolve the matrix (agarose) as well as the running buffer. 


TLS Online TPP Program

#Id: 2479

#Unit 13. Methods in Biology

Separation of RNA, TRIS-borate with EDTA ( TBE) is typically used due to superior buffering capacity (beneficial for long run times).