Description
PCR: polymerase chain reaction. Denature (95°C) → anneal primers (50–65°C) → extend (72°C). Repeat 25–35 cycles. Amplifies target DNA exponentially. Requires template, primers, dNTPs, Taq polymerase, buffer.
Protocol Flowchart
graph TD
A[Template DNA] --> AND1{All components
required?} B[Primers] --> AND1 C[dNTPs] --> AND1 D[Taq Polymerase] --> AND1 AND1 --> Prep[Prepare reaction mix] Prep --> Init[Initial denature 95°C 2-5 min] Init --> Cycle[Cycle 25-35x] Cycle --> Den[Denature 95°C 30 s] Den --> Ann[Anneal 50-65°C 30 s] Ann --> Ext[Extend 72°C 1 min/kb] Ext --> Cycle Cycle --> Hold[Final extension 72°C 5 min] Hold --> Cool[Hold 4°C] Cool --> Out[Amplified product] style A fill:#ff6b6b,stroke:#c92a2a,color:#fff style B fill:#ff6b6b,stroke:#c92a2a,color:#fff style C fill:#ff6b6b,stroke:#c92a2a,color:#fff style D fill:#ff6b6b,stroke:#c92a2a,color:#fff style Prep fill:#51cf66,stroke:#2f9e44,color:#fff style Init fill:#51cf66,stroke:#2f9e44,color:#fff style Cycle fill:#74c0fc,stroke:#1971c2,color:#fff style Den fill:#51cf66,stroke:#2f9e44,color:#fff style Ann fill:#51cf66,stroke:#2f9e44,color:#fff style Ext fill:#51cf66,stroke:#2f9e44,color:#fff style Hold fill:#51cf66,stroke:#2f9e44,color:#fff style Cool fill:#74c0fc,stroke:#1971c2,color:#fff style Out fill:#b197fc,stroke:#7950f2,color:#fff style AND1 fill:#b4b4dc,stroke:#8b8bc4,color:#000
required?} B[Primers] --> AND1 C[dNTPs] --> AND1 D[Taq Polymerase] --> AND1 AND1 --> Prep[Prepare reaction mix] Prep --> Init[Initial denature 95°C 2-5 min] Init --> Cycle[Cycle 25-35x] Cycle --> Den[Denature 95°C 30 s] Den --> Ann[Anneal 50-65°C 30 s] Ann --> Ext[Extend 72°C 1 min/kb] Ext --> Cycle Cycle --> Hold[Final extension 72°C 5 min] Hold --> Cool[Hold 4°C] Cool --> Out[Amplified product] style A fill:#ff6b6b,stroke:#c92a2a,color:#fff style B fill:#ff6b6b,stroke:#c92a2a,color:#fff style C fill:#ff6b6b,stroke:#c92a2a,color:#fff style D fill:#ff6b6b,stroke:#c92a2a,color:#fff style Prep fill:#51cf66,stroke:#2f9e44,color:#fff style Init fill:#51cf66,stroke:#2f9e44,color:#fff style Cycle fill:#74c0fc,stroke:#1971c2,color:#fff style Den fill:#51cf66,stroke:#2f9e44,color:#fff style Ann fill:#51cf66,stroke:#2f9e44,color:#fff style Ext fill:#51cf66,stroke:#2f9e44,color:#fff style Hold fill:#51cf66,stroke:#2f9e44,color:#fff style Cool fill:#74c0fc,stroke:#1971c2,color:#fff style Out fill:#b197fc,stroke:#7950f2,color:#fff style AND1 fill:#b4b4dc,stroke:#8b8bc4,color:#000
Color Scheme (6-Color System)
Red
Triggers & Inputs
Triggers & Inputs
Yellow
Structures & Objects
Structures & Objects
Green
Processing & Operations
Processing & Operations
Blue
Intermediates & States
Intermediates & States
Violet
Products & Outputs
Products & Outputs
Lavender
Decision Diamonds (OR/AND)
Decision Diamonds (OR/AND)
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📊 Scientific Accuracy
This flowchart is based on verified molecular biology protocols from peer-reviewed literature and standard lab manuals. Denaturation, annealing, and extension temperatures and conditions have been validated against primary sources. The model represents the current consensus on PCR as a core molecular biology technique.
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📚 Sources & Citations
Mullis KB, Faloona FA. Specific synthesis of DNA in vitro via a polymerase-catalyzed chain reaction.
Methods in Enzymology. 1987.
Saiki RK, Gelfand DH, Stoffel S, et al. Primer-directed enzymatic amplification of DNA with a thermostable DNA polymerase.
Science. 1988.
Green MR, Sambrook J. Molecular Cloning: A Laboratory Manual. 4th ed. Cold Spring Harbor Laboratory Press. 2012.
Standard reference for PCR protocols.
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📋 Metadata
| Process ID | assay_protocols-pcr |
| Created | 2026-03-15 |
| Verified | ✅ Yes |
| Last Updated | 2026-03-15 |
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Process Statistics
Nodes: 15 | Edges: 15 | OR Gates: 0 | AND Gates: 1