PCR protocols

PCR protocols

 

Note: This is a quick-start protocol. It does not provide the full information about each enzyme. Please refer to the online manual for detailed information about individual enzymes.

 

Note: To determine the volume of your PCR reactions, 20 ul is normally used when the PCR product purification step is not necessary. For example: colony PCR. 50 ul is used when you need to purify your PCR product.​​ 

 

  • Go Taq Green​​ 

Go Taq green is great for applications that do not required high fidelity of the DNA Polymerase. It’s good for colony PCR, or as a control when your PCR reaction doesn’t work.​​ Also, it comes with a dye. So no need to add DNA loading dye after your PCR reaction.

 

Recipe:

Template: x ul

100 uM Primer 1: 0.4 ul

100 uM primer 2: 0.4 ul

2X Go Taq Green Master Mix: 10 ul

ddH2O: to make it 20 ul

Total volume: 20 ul

 

Note: For beginners, pipetting 0.4 ul liquid is challenging. Instead, dilute 100 uM primer ten folds to 10 uM in a new 1.5 ml tube and add 4 ul of each primer to the reaction. Keep the 10 uM​​ primer at -20C for future use.

 

Thermo cycle:​​ 

  • 95°C: ​​ 30​​ sec to 3​​ min (If you use whole E.​​ coli cell as the template, do 3​​ min denaturing)

  • 95°C: 30​​ sec

  • 54°C: 30​​ sec (the annealing temperature depends on your primer Tm)

  • 72°C: 1kb/min

  • repeat from step 2, 35 cycles total

  • 72°C: 10 min

  • 12°C: forever

 

  • Phusion​​ 

Phusion enzyme is a high-fidelity DNA polymerase. It’s great for​​ amplifying genes for cloning. Phusion is​​ very fast too. However, I found Phusion is not as robust as Taq, especially if your PCR product exceeds 2 kb.

 

Recipe:

Template: x ul

100 uM Primer 1: 0.4 ul

100 uM primer 2: 0.4 ul

5x HiFi Buffer: 10 ul

10​​ mM dNTP: 1 ul

Phusion Enzyme: 0.5​​ uL

ddH2O:​​ to make it 50 ul

Total volume: 50 ul

 

Note: For beginners, pipetting 0.4 ul liquid is challenging. Instead, dilute 100 uM primer ten folds to 10 uM in a new 1.5 ml tube and add 4 ul of each primer to the reaction. Keep the 10 uM​​ primer at -20C for future use.

 

Thermo cycle:​​ 

  • 98°C: ​​ 30 sec​​ 

  • 98°C: 10 sec

  • 56°C: 30 sec (the annealing temperature depends on your primer Tm+ 3°C)

  • 72°C: 1 kb/15 sec

  • repeat from step 2, 35 cycles total

  • 72°C: 10 min

  • 12°C: forever

 

Note: Phusion also comes with a high GC buffer. If you encounter problems with PCR, especially for high GC template and large PCR product, try GC buffer or adding 3 ul DMSO.

 

  • Platinum Taq

Platinum Taq is also a high-fidelity DNA polymerase. I found it more robust than Phusion, but it is slower too.​​ It extends DNA at 68°C instead of 72°C.

 

Recipe:

Template: x ul

100 uM Primer 1: 0.4 ul

100 uM primer 2: 0.4 ul

10x Pt Taq buffer​​ (labeled 10x HiFi buffer): 5 ul

50 mM MgSO4: 2 ul

Platinum Taq: 0.3 ul

10​​ mM​​ dNTP: 1 ul

ddH2O: to make it 50 ul

Total volume: 50 ul​​ 

 

Note: For beginners, pipetting 0.4 ul liquid is challenging. Instead, dilute 100 uM primer ten folds to 10 uM in a new 1.5 ml tube and add 4 ul of each primer to the reaction. Keep the 10 uM primer at -20C for future use.

 

Thermo cycle:​​ 

  • 94°C:​​ ​​ 30​​ sec-3 min​​ (If you use whole E. coli cell as the template, do 3 min denaturing)

  • 94°C: 30 sec

  • 54°C: 30 sec (the annealing temperature depends on your primer Tm)

  • 68°C: 1​​ kb/min

  • repeat from step 2, 35 cycles total

  • 68°C: 10 min

  • 12°C: forever

 

Note: For longer PCR products: Try adding 3 ul DMSO if your PCR didn’t work for longer products.

 

 

Zhen

12/19/17