Ask a Question
Top Posters
Since Sunday
New Topic  
Posts: 2
Rep: 0 0
7 months ago
rAbs are constructed in vitro, outside the constraints of the immune system, using recombinant DNA technologies. The antibody genes are isolated and then incorporated into plasmid DNA vectors, and the resulting plasmids are transferred into expression hosts such as bacteria, yeast, or mammalian cell lines. rAbs can be used in all applications where classical mAbs are used.

1. They require less purified antigen to produce than classical mAbs.
2. The production time of rAbs is weeks vs months for mAbs, and rAb production is amenable to high-throughput processing.
3. Unlike mAbs, rAbs can be constructed against virtually any antigen, including human and highly conserved antigens (not recognized as foreign by the mouse’s immune system), as well as non-immunogenic (do not elicit an immune response) and toxic molecules (cannot be injected into the mouse host).
4. rAbs circumvent the human immune response elicited by murine mAbs. If administered to humans, a mAb (even a “humanized” one) will appear as foreign to the human immune system, and will cause an adverse hypersensitivity reaction.
5. rAbs can be produced in several formats: Fab fragments (the antibody’s “arms”), single-chain variable region fragments (scFv, consist solely of the antibody’s binding site), diabodies (dimeric scFvs), and can be expressed in several hosts: coli, mammalian cells, yeast, fungi, insect cells, and even plants. are particularly quick and inexpensive.
6. rAbs are amenable to fusion with drugs and toxins, and can thus be used in therapeutics.
7. rAbs circumvent the need to immortalize B-cells in the form of hybridomas. Remember that hybridomas are not normal cells, and have an unusual assortment of chromosomes, the loss of which can occur at any time during the culture process. In fact, anyone who has worked with hybridomas can tell you that these finicky, supposedly immortal cells can die off, not grow when taken out of cryogenic storage, or simply decide to stop secreting the mAb (due to loss of antibody genes). All of these obstacles are bypassed by rAbs, which are constructed by isolation of the respective antibody genes. If you have access to an antibody gene, you will have at your disposal an unlimited source of the antibody itself; all you would need is a protein expression platform.
8. rAbs are defined by the sequences that encode them, making them more reliable, and providing more reproducible results than mAbs.
9. rAbs can be readily optimized, as their nucleic acid sequences are defined and readily accessible. Do you need to improve the affinity of your rAb? No problem! Affinity maturation of rAbs, often to levels unattainable by mAbs, is possible through several molecular biology techniques such as error-prone PCR and site-directed mutagenesis.
10.The selection process for rAbs is highly flexible and can be adjusted to favor the isolation of antibodies with specific properties. With classical mAb production, the level of control you have over the process stops as soon as the immunogen is injected into the animal. From there on, you are at the mercy of the mouse’s immune system, which will dictate how the mAb is built, selected, and optimized for binding. This is why mAbs need to be extensively characterized to ensure that you have a mAb against the intended antigen. Moreover, mAb-producing hybridomas need to undergo single-cell cloning, a laborious, time-consuming, often frustrating process.
11. Mass production of rAbs does not require the use of animals (as is the case with ascites production of mAbs), and thus overcomes ethical concerns over animal distress, discomfort, and pain. In fact, the production of some
Read 141 times
New Topic      
Hold tight!  A Biology Forums Expert has been contacted to start answering this thread.
Share This Topic
Similar topics that might interest you...
Nursing and Clinical   2 years ago   Chippewas   houston1994   3 Replies   67 Views
Biochemistry   11 months ago   shoppa   freddieg23   1 Reply   19 Views
Biochemistry   11 months ago   hawkins1346   hollyhateschool   1 Reply   22 Views
Biochemistry   11 months ago   bdiddydog   dalveixes   1 Reply   20 Views
4 More
Post your homework questions and get free online help from our incredible volunteers.
Learn More
Improve Grades
Help Others
Save Time
Accessible 24/7
  92 People Browsing
Related Images
Your Opinion
Who's your favorite biologist?
Votes: 5