Steps of recombinant DNA technologyपुनर्योगज DNA तकनीक के चरण
NCERT Fig 9.2 · Class 12 Biology · Chapter 9 · interactive diagram
Parts and their functions
- Isolation of DNA (DNA का पृथक्करण) — Break cells with enzymes (lysozyme – bacteria, cellulase – plant cells, chitinase – fungus); remove RNA with ribonuclease and proteins with protease; purified DNA precipitates with chilled ethanol as fine threads (spooling).
- Cutting at specific locations (विशिष्ट स्थानों पर काटना) — Purified DNA + restriction enzyme at optimal conditions; progress checked by agarose gel electrophoresis; the band is cut out and eluted.
- Amplification by PCR (PCR द्वारा प्रवर्धन) — Many copies of the gene of interest are made in vitro using primers and Taq polymerase.
- Ligation into vector (संवाहक में जोड़ना) — Vector cut with the same enzyme; gene and vector joined by DNA ligase → recombinant DNA.
- Insertion into host (परपोषी में प्रवेश) — Host cells made competent (e.g. calcium ions, then heat shock); or micro-injection (animal cells), biolistics/gene gun (plants), disarmed pathogen vectors.
- Selecting transformants (रूपांतरित कोशिकाओं का चयन) — Selectable markers (e.g. ampicillin resistance) and insertional inactivation (blue–white) separate recombinants from non-recombinants.
- Obtaining the foreign gene product (बाहरी जीन उत्पाद प्राप्त करना) — The protein made from the foreign gene is a recombinant protein; large volumes are grown in bioreactors (also continuous culture in log phase).
- Downstream processing (अनुप्रवाह संसाधन) — Separation and purification of the product, formulation with preservatives, clinical trials for drugs and strict quality control.
Original diagram drawn by Simple Learning Hub, based on NCERT Fig 9.2. Report a mistake