<?xml version="1.0" encoding="utf-8" standalone="yes"?><rss version="2.0" xmlns:atom="http://www.w3.org/2005/Atom"><channel><title>Difficult Template on Michael’s Domain</title><link>https://jeltsch.org/en/tags/difficult-template/</link><description>Recent content in Difficult Template on Michael’s Domain</description><generator>Hugo</generator><language>en-us</language><copyright>Copyright © 2002 - 2026 Michael Jeltsch.</copyright><lastBuildDate>Fri, 24 Jul 2026 00:18:18 +0300</lastBuildDate><atom:link href="https://jeltsch.org/en/tags/difficult-template/index.xml" rel="self" type="application/rss+xml"/><item><title>Kapa HiFi excels, Phusion works sort-of, Q5 and Platinum SuperFi disappoint</title><link>https://jeltsch.org/en/kapa_hifi_excels_phusion_works_sort_of_q5_and_platinum_superfi_disappoint/</link><pubDate>Fri, 02 Dec 2016 00:00:00 +0000</pubDate><guid>https://jeltsch.org/en/kapa_hifi_excels_phusion_works_sort_of_q5_and_platinum_superfi_disappoint/</guid><description>&lt;p&gt;My last 
 &lt;a href="https://www.neb.com/products/e5520-nebuilder-hifi-dna-assembly-cloning-kit" target="_blank" rel="noopener noreferrer nofollow"&gt;NEBuilder assembly&amp;nbsp;






 
 
 
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 got stuck because I couldn&amp;rsquo;t get two of the PCR reactions to work. I needed one small fragment and two ~3-kb-fragments. I needed to insert a 2A-sequence in between the small and one of the 3-kb-fragments and thus added the necessary sequences as tails to the primers. The template was not especially GC-rich, nothing too complicated, but only the small fragment did amplify in my first attempt. When also my second attempt failed to amplify the 3-kb-fragments, I decided to try out some alternative polymerases. For cloning purposes, I have been using exclusively Phusion High Fidelity DNA polymerase (from 
 &lt;a href="https://www.neb.com/products/m0530-phusion-high-fidelity-dna-polymerase" target="_blank" rel="noopener noreferrer nofollow"&gt;New England Biolabs&amp;nbsp;






 
 
 
 &lt;svg class="svg-inline--fa fas fa-up-right-from-square fa-2xs" fill="currentColor" aria-hidden="true" role="img" viewBox="0 0 512 512" overflow="visible"&gt;&lt;use href="#fas-up-right-from-square"&gt;&lt;/use&gt;&lt;/svg&gt;&lt;/a&gt;
 or from 
 &lt;a href="https://www.thermofisher.com/order/catalog/product/F530S" target="_blank" rel="noopener noreferrer nofollow"&gt;ThermoFisher&amp;nbsp;






 
 
 
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) for the last years, but maybe there was something better and more robust? I received three different free samples for testing: 
 &lt;a href="https://www.kapabiosystems.com/product-applications/products/pcr-2/kapa-hifi-pcr-kits/" target="_blank" rel="noopener noreferrer nofollow"&gt;KAPA HiFi HotStart&amp;nbsp;






 
 
 
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, 
 &lt;a href="https://www.neb.com/products/m0491-q5-high-fidelity-dna-polymerase" target="_blank" rel="noopener noreferrer nofollow"&gt;NEB Q5® High-Fidelity&amp;nbsp;






 
 
 
 &lt;svg class="svg-inline--fa fas fa-up-right-from-square fa-2xs" fill="currentColor" aria-hidden="true" role="img" viewBox="0 0 512 512" overflow="visible"&gt;&lt;use href="#fas-up-right-from-square"&gt;&lt;/use&gt;&lt;/svg&gt;&lt;/a&gt;
 and 
 &lt;a href="https://www.thermofisher.com/order/catalog/product/12351010?ICID=search-product" target="_blank" rel="noopener noreferrer nofollow"&gt;ThermoFisher Platinum SuperFi™&amp;nbsp;






 
 
 
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. My graduate student did the PCRs yesterday and I ran the gels today. From the gel quality, you can see that I don&amp;rsquo;t have much routine anymore, but the overall results are quite clear and in the future, our go-to polymerase for tricky templates will be KAPA. I think KAPA&amp;rsquo;s proofreading capabilities are a bit below Phusion, but I do not care if 2% instead of 0.5% of the DNA products contain a mutation.In the attached PDF file, you can see, that my grad student included two more samples for the Phusion polymerase, where she used the same conditions, but a different template (supercoiled plasmid instead of linear DNA). Surprisingly, the Phusion polymerase did a much better job to amplify from supercoild DNA than from (the same) linear DNA; I cannot explain that…&lt;/p&gt;</description></item></channel></rss>