Blocking primers to enhance PCR amplification of rare sequences in mixed samples – a case study on prey DNA in Antarctic krill stomachs
2008

Enhancing PCR for Prey DNA in Antarctic Krill Stomachs

Sample size: 13 publication Evidence: high

Author Information

Author(s): Hege Vestheim, Simon N. Jarman

Primary Institution: Department of Biology, University of Oslo; Australian Antarctic Division

Hypothesis

Can blocking primers improve the PCR amplification of rare prey DNA in the presence of dominant predator DNA?

Conclusion

The study presents a method that effectively amplifies prey DNA while blocking predator DNA in PCR mixtures.

Supporting Evidence

  • The method reduced predator amplicons to undetectable levels even when predator template was present in 1000-fold excess.
  • Adding blocking primers allowed for the successful amplification of prey DNA.
  • 111 clones from 13 different krill stomachs revealed 36 different sequences.

Takeaway

Scientists found a way to make sure they can see the food that krill eat by blocking the DNA from the krill itself when they look for the DNA of the food.

Methodology

The study involved designing blocking primers to prevent the amplification of predator DNA while allowing prey DNA to be amplified in PCR.

Potential Biases

The blocking primers may inadvertently block other non-target species' DNA.

Limitations

The method may not completely eliminate the risk of amplifying other species' DNA, and the complete sequence coverage of potential prey was not available.

Participant Demographics

The study focused on Antarctic krill and their dietary analysis.

Digital Object Identifier (DOI)

10.1186/1742-9994-5-12

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