Biotechnology in Medicine: Recombinant Therapeutics
Biology · Biotechnology and Its Applications · NEET
Recombinant therapeutics are medicines (like human insulin) made by putting a human gene into bacteria or other organisms using recombinant DNA (rDNA) technology. Because they are the same as human proteins, they do not cause allergy or infection, unlike drugs taken from animals. NCERT fact to remember: about 30 recombinant therapeutics have been approved for human use worldwide. Memory hook: "recombinant = safe copy of a human protein."
Recombinant therapeutic pathway: a human gene is inserted into a host (E. coli), the host makes the human protein, which is purified into medicine. Because it is identical to the human protein, it causes no allergy or infection.
Your doubts, answered
What exactly is a recombinant therapeutic?
It is a therapeutic protein (a medicine) produced using recombinant DNA technology. A human gene is put into a host organism such as E. coli, and the organism makes the human protein in large amounts. Human insulin (Humulin) is the classic example. The word 'recombinant' just means the DNA was joined together in the lab from different sources.
Why do recombinant therapeutics not cause allergy or unwanted immune reactions?
Because they are identical to human proteins. NCERT states that since recombinant therapeutics are identical to human proteins, they do not induce unwanted immunological responses. Earlier, insulin taken from cattle and pigs was slightly different from human insulin, so some patients got allergic reactions. The recombinant version removes this problem.
How many recombinant therapeutics are approved for human use?
NCERT says about 30 recombinant therapeutics have been approved for human use the world over. This exact number is a favourite one-line fact for NEET, so remember 'about 30'.
Are recombinant therapeutics also free from infection risk?
Yes. NCERT notes they are free from the risk of infection that was seen in similar products isolated from non-human (animal) sources. Animal-derived products could carry infections; a protein made inside cultured bacteria and purified does not carry animal pathogens.
Is recombinant insulin the only recombinant therapeutic?
No. Insulin (Humulin) is the most famous NEET example, but 'about 30' such medicines are approved. Insulin is used as the main example in NCERT because it was one of the first and shows every step clearly. For NEET, know insulin in detail and know the general facts about the whole group.
⚠️ The NEET trap ✗ Recombinant therapeutics are safer only because they are made cheaply in bacteria. ✓ They are safer because they are identical to human proteins, so they cause no unwanted immune (allergy) response and carry no infection from animal sources. 🧠 NEET tests the REASON (identical to human protein), not the cost. Cost is a bonus, not the safety reason.
Real NEET questions
2016
Which of the following statements is not correct?
A · The functional insulin has A and B chains linked together by hydrogen bonds ✓
B · Genetically engineered insulin is produced in E. coli
C · In man insulin is synthesised as a proinsulin
D · The proinsulin has an extra peptide called C-peptide
Solution: Insulin's A and B chains are linked by disulphide bridges, not hydrogen bonds, so statement (A) is incorrect. The other three statements are true: recombinant insulin is made in E. coli, insulin is first made as proinsulin, and proinsulin has an extra C-peptide.
2022
Which statement(s) is/are correct about genetically engineered insulin? (a) Pro-hormone insulin contains extra stretch of C-peptide (b) A-peptide and B-peptide chains of insulin were produced separately in E. coli, extracted and combined by creating a disulphide bond between them (c) Insulin used for treating diabetes was extracted from cattle and pigs (d) Pro-hormone insulin needs to be processed for converting into a mature and functional hormone (e) Some patients develop allergic reactions to the foreign insulin
A · (a), (b) and (d) only ✓
B · (b) only
C · (c) and (d) only
D · (c), (d) and (e) only
Solution: For genetically engineered (recombinant) insulin: proinsulin has C-peptide (a), the A and B chains were made separately in E. coli and then joined by disulphide bonds (b), and proinsulin must be processed to become mature insulin (d). Statements (c) and (e) describe the OLD animal insulin, not the recombinant one, so they are excluded. Correct answer: (a), (b) and (d).
2025
Which of the following genetically engineered organisms was used by Eli Lilly to prepare human insulin?
A · Virus
B · Phage
C · Bacterium ✓
D · Yeast
Solution: In 1983 Eli Lilly introduced the DNA sequences coding for the A and B chains of human insulin into plasmids of E. coli, which is a bacterium, to produce the insulin chains. So the engineered organism is a bacterium.
Solved Biotechnology and Its Applications NEET PYQs
Try the real previous-year questions from this chapter — each with the answer and a full solution.
What is the difference between recombinant therapeutics and normal drugs?
Recombinant therapeutics are protein medicines made by rDNA technology using a host organism, and they are identical to human proteins. Ordinary chemical drugs are small molecules made by chemistry, not by inserting genes.
Give one example of a recombinant therapeutic for NEET.
Human insulin (Humulin), made by Eli Lilly using E. coli, is the standard NEET example.
Why was animal insulin a problem before recombinant insulin?
Insulin from cattle and pigs is slightly different from human insulin, so some patients developed allergic reactions. Recombinant human insulin removed this problem because it is identical to human insulin.
How many recombinant therapeutics are approved worldwide (NCERT)?
About 30 recombinant therapeutics have been approved for human use worldwide, according to NCERT.
