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I've heard that LAMP could be a good alternative to PCR for DNA strand amplification and detection because the equipment required is cheaper, more portable, and the amplification is faster since all happens at a single temperature.

Since this system has clear advantages, I'm curious what are the downsides that prevent it from completely overtaking PCR/qPCR?

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5862059/ mentions some disadvantages:

However, this technique has some limitations. Complexity of multiple primers’ designs for multiplication of new gene regions and selecting the suitable regions in the gene sequence for efficient design of primers, complicated product having cauliflower-like structures with different sizes, lack of commercial kits based on LAMP technique and complexity of this method mechanism are some of its drawbacks limiting its popularity among the researchers; and it not as common as PCR-based method.

but they just don't seem that important compared to the large benefits for diagnostic usage.

For example, from this video https://www.youtube.com/watch?v=L5zi2P4lggw I understand that more primers are needed, but is it that hard to "just create a few more primers"? Aren't those just deterministically determined from the target DNA of interest in this case?

I can see why the cauliflower structures matter for certain applications, e.g. I guess those messy strands are not going to go through an Oxford Nanopore pore for sequencing, but do they matter when we just want to know if the DNA of interest is present or not?

Related articles:

I later learnt that there are other isothermal amplification amplification schemes out there as well, maybe I knew about those I would have asked a more generic isothermal question:

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Having to use more primers is definitely one of the big reasons. Primer design is difficult and time-consuming, and even more so if you're dealing with similar targets. For instance, if you're trying to differentiate closely related bacterial strains, having to design primers for 6 or 8 regions instead of just two is going to lower your ability to differentiate the strains. It's even worse if you're working with viruses - these mutate quickly and therefore your LAMP primers will fail to amplify the virus sooner than normal PCR primers.

LAMP is good because it's cheap and portable, but there are portable PCR thermocyclers starting to be produced (eg. miniPCR, Biomeme) and so diagnostically speaking, it's a lot easier to just use existing PCR primers that have been validated and are widely used, instead of creating new primers that you'll have to validate all over again.

The primers again are important if you're trying to amplify multiple targets - it's a lot easier to create degenerate or consensus primers for a standard PCR than it is for LAMP, and also easier to distinguish multiple target bands on a gel, which isn't possible for LAMP.

It can vary, but in my personal experience, I have always found Taqman-based PCR to be more sensitive than LAMP. You can't use Taqman probes with LAMP. You also can't use LAMP for cloning, and melt-curve analysis isn't possible with LAMP, which is useful for detecting primer dimers and diagnostically for distinguishing between targets.

So, LAMP is good because it's cheap, requires less equipment, can be done in the field with minimal reagents, and tends to be more robust than PCR as it is less prone to be affected by inhibitors. This means it is great for in-field diagnostics in developing regions. But there is a range of things PCR can do that LAMP can't, and the complex primer design alone will prevent it from overtaking PCR.

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Nice answer teaelleceecee. Conventional PCR primers ultimately misfire against a mismatched exclusive target especially if it is at high copy #. Multiply exclusive mismatched LAMP primers won't do that. True that viral mutations may stop such a LAMP assay. Design in conserved sequence may help with this. Microfluidic systems will allow for "multiplexing" using geographic separation, which could allow for multiple amplimers to overcome the former challenge. There are tricks to achieving single copy LAMP. PCR suffers from inhibitor retarded polymerase being slowed down such that it doesn't reach the opposing primer site before denaturation. In LAMP, there is no denaturation step, which mostly explains its robustness to inhibition.

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