X-Linked Recessive Trait

a. Usually more males than females are affected.

b. Affected sons are usually born to unaffected mothers; thus, the trait skips generations.

c. Approximately half of a carrier (heterozygous) mother’s sons are affected.

d. Never passed from father to son.

e. All daughters of affected fathers are carriers.

#Id: 2488

#Unit 13. Methods in Biology

Low-percentage acrylamide gels are also used to separate DNA. Gels of between 10 and 20% acrylamide are used in techniques such as SDS–gel electrophoresis, where the smaller pore size now introduces a sieving effect that contributes to the separation of proteins according to their size. 

#Id: 2489

#Unit 13. Methods in Biology

Sodium Dodecyl Sulfate (SDS)-Polyacrylamide Gel Electrophoresis is based on the separation of proteins according to size, it can also be used to determine the relative molecular mass of proteins.

#Id: 2490

#Unit 13. Methods in Biology

SDS (H3C-(CH2 )10 –CH2 -OSO3 – Na+ ) is an anionic detergent used to create negative on sample  On average, one SDS molecule binds for every two amino-acid residues.

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#Unit 13. Methods in Biology

SDS–PAGE are firstly boiled for 5 min in sample buffer containing - mercaptoethanol or dithiothreitol ( DTT) and SDS. Mercaptoethanol or DTT reduce any disulfide bridges

#Id: 2492

#Unit 13. Methods in Biology

In conventional discontinuous gel electrophoresis two type of GEL system is used on top with comb there is a stacking gel with pH 6.8 and below resolving with gel pH 8.8 phenomenon known as isotachophoresis.

#Id: 2493

#Unit 13. Methods in Biology

The band-sharpening effect relies on the fact that negatively charged glycinate ions (in the electrophoresis buffer) have a lower electrophoretic mobility than do the protein–SDS complexes, which, in turn, have lower mobility than the chloride ions (Cl − ) of the loading buffer and the stacking gel buffer.