Ligase Chain Reaction: Sensitivity

Keith Robison robison at
Wed Dec 4 21:18:08 EST 1991

bhjelle at (Brian Hjelle) writes:

>Pretty soon everyone will have read the blurb in Science about the
>wonders of LCR. 

>I was ready to give it a serious shot (my PCR primer bill is already
>as large as the GNP of some countries) but was put off by a comment
>near the end that LCR was less sensitive than PCR.

>Is LCR really less sensitive than PCR, all else being equal?

>Before you answer, let me just say that sensitivity is a big issue
>in my lab, because we are looking for viral DNA that is 100-1000X 
>less abundant than a single-copy mammalian gene, or about 1 part
>in  3  billion. We frequently try new primers that turn out to be
>useless because of low sensitivity, even after lots of "optimization".


According to the original paper (see below), LCR can definitely detect 200
target sequences in a sample.  Whether it can go lower wasn't tested.

LCR won't lower your primer bill, as you still have to make oligos. 
However, you don't need any nucleotides.

F. Barany.   1991.  Genetic disease detection and DNA amplification using 
   cloned thermostable ligase.  PNAS 88:189-193

Keith Robison
Harvard University
Program in Biochemistry, Molecular, Cellular, and Developmental Biology

robison at

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