Mnemonic Collection

1. PCR Steps and Temperatures — "DAE: 94-55-72"

• D = Denaturation — 94°C (Divide the strands)
• A = Annealing — 55°C (Attach the primers)
• E = Extension — 72°C (Elongate the strand)
• "94 → cools to 55 → warms to 72: Drop then Rise"

2. pBR322 Features — "OARS"

• O = Ori (origin of replication)
• A = AmpR (ampicillin resistance)
• R = Restriction sites (multiple cloning sites)
• S = Second marker = TetR (tetracycline resistance)
• "pBR322 rows its OARS through the cloning sea"

3. EcoRI — "Go Ahead And Trim The Code"

• G-A-A-T-T-C → Go-Ahead-And-Trim-The-Code
• Cuts between G and A: G↓AATTC
• Leaves 5'-AATT sticky ends (4 nucleotides)

4. DNA Electrophoresis Direction — "DNA is Negative, Needs the Anode (Positive)"

• DNA = Negative charge (phosphate backbone)
• Negative → moves toward Positive (Anode)
• "DNA NeeDs Anode" (D.N.A. = needs anode)

5. DNA Isolation Steps — "LRPEP"

• L = Lysozyme (cell wall lysis)
• R = RNase (RNA removal)
• P = Protease (protein removal)
• E = Ethanol precipitation
• P = Purified DNA
• "Lyse Really Pure Every Protocol"

6. Transformation Methods — "CMBE"

• C = CaCl2 + heat shock (bacteria)
• M = Microinjection (animal cells)
• B = $\frac{Biolistics}{gene}$ gun (plants, organelles)
• E = Electroporation (versatile)
• "Can Most Bacteria Enter?"

7. pBR322 Insertional Inactivation Result

• Recombinant: "Amp Yes, Tet No" → tetR disrupted
• Non-recombinant: "Amp Yes, Tet Yes" → both intact
• Untransformed: "Amp No" → no plasmid at all

8. Restriction Enzyme Naming (EcoRI)

• Eco = Escherichia coli
• R = strain RY13
• I = first enzyme from this strain
• "Every Character Reads Identically" (palindrome reminder)