Flashcards For NEET Biology - Biotechnology: Principles and Processes

Recombinant DNA (rDNA) is used

An organism with a desired trait is generated

E.g. vitamins, vaccines, antibiotics, etc.

E.g. commonly present in bacteria

Stanley Cohen and Herbert Boyer produced the first artificial rDNA by adding antibiotic-resistant genes to the plasmid of Salmonella typhimurium

They cut the DNA at a specific palindromic sequence forming sticky ends

Werner Arber, Hamilton Smith, and Daniel Nathans discovered

Hind II– the first restriction endonuclease

Recognition site, where the enzyme cuts is G/AATTC (5’→3’) and in the complementary strand it is CTTAA/G (3’→5’)

Discovered in Boyer’s UCSF lab

Joins Okazaki fragments of lagging strand during replication

Carried out gene-splicing experiments

Added genes of lambda phage virus into DNA of SV-40 virus

Received Nobel prize in 1980

E.g. plasmids (pBR322, Ti), bacteriophages (λ phage)

Origin of replication- ori

Selectable markers- ampicillin and tetracycline resistant genes, i.e. amp^R and tet^R

Restriction sites- BamH I, Sal I (in tet^R gene), Hind III, EcoR I, Pvu II, Pst I (in amp^R gene), Cla I, etc.

The oligonucleotide primer is used after denaturation- Annealing

Primer is extended using thermostable DNA polymerase, i.e. Taq polymerase isolated from Thermus aquaticus (bacterium)

Using vector

Without vector- microinjection (direct injection of rDNA into the nucleus of animal cells)

Biolistics or gene gun- plant cells are bombarded with microparticles of gold or tungsten coated with DNA