Question

1)ELISA is widely used as the initial screening test for diseases such as HIV, lupus, and Lyme disease. How would western blot be used in the diagnostic workflow?

2) Why are Precision Plus Protein Kaleidoscope standards run alongside the protein samples in the gel?

3)  In a complex organism, is it possible for a single gene to encode for multiple proteins? If yes, explain.

Answer 1

Answer (1)

• Both ELISA as well as western blotting are blood antibodies detection test that may detect HIV , lupus and lyme disease.
• Western blotting test is used as a confirmatory test to confirm the results of ELISA for dignosis.
• western blotting can detect specific protein in mixture of different proteins.
• Western blotting (also known as immunoblotting) can measure several antibodies against the different proteins.
• Western blotting techniques use antibodies which can detect any protein of interest for dignostic purpose.
• Lyme disease is caused by borrelia (bacteria), by western blotting we can detect bacteria's specific antigens that are the specialized marker of bacteria and positive result indicates the presence of infection inside the body.

Answer (2)

• Precision Plus Protein Kaleidoscope standards are used for the determination of molecular weight of protein samples.
• Ability to visualize this standards on the gel can helps in the monitoring of protein samples during gel electrophoresis.
• This also provides efficiency in detecting the transfer or proteins to the membrane (gel to membrane transfer in western blotting).

Answer (3)

Yes, it is possible for single gene to encode for multiple proteins due the presence of regulated processes such as alternative splicing or differential splicing which occurs during gene expression.

In simple splicing mechanism that occurs in the pre-mRNA to make mature RNA, introns region (non-coding) are removed from the gene sequence and exons (coding region) of the gene joined and results in the production of a functional protein.

In alternative splicing, along with introns some exons are also removed or spliced out that causes the joining of different exons together and results in the generation of different functional proteins.