CBSE · Class 12 · Biology · Chapter 9

Biotechnology: Principles and Processes — Formula Sheet

Board Formulas

10 formulas

1.Central rDNA Equation★
$Insert DNA + Vector Ligase Recombinant DNA$
Restriction enzyme cuts both — DNA ligase seals the sticky ends.
2.Restriction Enzyme Naming★
$Eco RI: E = Escherichia, co = coli, R = strain RY13, I = first isolated$
First letter of genus + first two of species (italicised) + strain + Roman numeral.
3.Palindromic Recognition Sequence
$5^{'} - GAATTC - 3^{'} / 3^{'} - CTTAAG - 5^{'}$
Reads the same 5' → 3' on both strands. Eco RI cuts between G and A leaving sticky ends.
4.PCR Cycle Equation★
$N = N_{0} \times 2^{n}$
After n cycles the template is amplified 2ⁿ-fold. 30 cycles ⇒ about 10⁹-fold amplification.
5.Ideal Cloning Vector Features★
$Vector = ori + selectable marker + MCS + small size$
ori = origin of replication; MCS = multiple cloning site; selectable marker distinguishes transformants.
6.Bioreactor Design Rule
$V_{stirred-tank} \approx 100 - 1000 L; O_{2} transfer via sparger + impeller$
Provides optimum temperature, pH, aeration and substrate to microbes.
7.Selectable Marker Example (pBR322)★
$amp^{R}, tet^{R}$
Antibiotic resistance genes let researchers select cells with recombinant vector.
8.Downstream Processing
$Separation + purification + formulation + quality control$
The steps after fermentation that give the marketable product.
9.Ti Plasmid and Agrobacterium
$Agrobacterium tumefaciens \to Ti plasmid \to disarmed transfer of DNA to plants$
Nature's own genetic engineer — used to make transgenic crops.
10.Gel Electrophoresis Movement
$DNA (negatively charged) + electrode migrates through agarose$
Smaller fragments move farther. Visualised with ethidium bromide under UV light.