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Yang Z, Le JT, Hutter D, Bradley KM, Overton BR, McLendon C, Benner SA. Eliminating primer dimers and improving SNP detection using self-avoiding molecular recognition systems. Biol Methods Protoc 2020; 5:bpaa004. [PMID: 32395633 PMCID: PMC7200914 DOI: 10.1093/biomethods/bpaa004] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Revised: 02/04/2020] [Accepted: 02/07/2020] [Indexed: 01/25/2023] Open
Abstract
Despite its widespread value to molecular biology, the polymerase chain reaction (PCR) encounters modes that unproductively consume PCR resources and prevent clean signals, especially when high sensitivity, high SNP discrimination, and high multiplexing are sought. Here, we show how "self-avoiding molecular recognition systems" (SAMRS) manage such difficulties. SAMRS nucleobases pair with complementary nucleotides with strengths comparable to the A:T pair, but do not pair with other SAMRS nucleobases. This should allow primers holding SAMRS components to avoid primer-primer interactions, preventing primer dimers, allowing more sensitive SNP detection, and supporting higher levels of multiplex PCR. The experiments here examine the PCR performances of primers containing different numbers of SAMRS components placed strategically at different positions, and put these performances in the context of estimates of SAMRS:standard pairing strengths. The impact of these variables on primer dimer formation, the overall efficiency and sensitivity of SAMRS-based PCR, and the value of SAMRS primers when detecting single nucleotide polymorphisms (SNPs) are also evaluated. With appropriately chosen polymerases, SNP discrimination can be greater than the conventional allele-specific PCR, with the further benefit of avoiding primer dimer artifacts. General rules guiding the design of SAMRS-modified primers are offered to support medical research and clinical diagnostics products.
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Affiliation(s)
- Zunyi Yang
- Foundation for Applied Molecular Evolution (FfAME), 13709 Progress Blvd, Box 7, Alachua, FL 32615, USA
- Firebird Biomolecular Sciences LLC, 13709 Progress Blvd, Box 17, Alachua, FL 32615, USA
| | - Jennifer T Le
- Foundation for Applied Molecular Evolution (FfAME), 13709 Progress Blvd, Box 7, Alachua, FL 32615, USA
| | - Daniel Hutter
- Firebird Biomolecular Sciences LLC, 13709 Progress Blvd, Box 17, Alachua, FL 32615, USA
| | - Kevin M Bradley
- Foundation for Applied Molecular Evolution (FfAME), 13709 Progress Blvd, Box 7, Alachua, FL 32615, USA
- Firebird Biomolecular Sciences LLC, 13709 Progress Blvd, Box 17, Alachua, FL 32615, USA
| | - Benjamin R Overton
- Foundation for Applied Molecular Evolution (FfAME), 13709 Progress Blvd, Box 7, Alachua, FL 32615, USA
| | - Chris McLendon
- Foundation for Applied Molecular Evolution (FfAME), 13709 Progress Blvd, Box 7, Alachua, FL 32615, USA
- Firebird Biomolecular Sciences LLC, 13709 Progress Blvd, Box 17, Alachua, FL 32615, USA
| | - Steven A Benner
- Foundation for Applied Molecular Evolution (FfAME), 13709 Progress Blvd, Box 7, Alachua, FL 32615, USA
- Firebird Biomolecular Sciences LLC, 13709 Progress Blvd, Box 17, Alachua, FL 32615, USA
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Flores-Juárez CR, González-Jasso E, Antaramian A, Pless RC. PCR amplification of GC-rich DNA regions using the nucleotide analog N4-methyl-2'-deoxycytidine 5'-triphosphate. Biotechniques 2016; 61:175-182. [PMID: 27712580 DOI: 10.2144/000114457] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Accepted: 07/06/2016] [Indexed: 11/23/2022] Open
Abstract
GC-rich DNA regions were PCR-amplified with Taq DNA polymerase using either the canonical set of deoxynucleoside triphosphates or mixtures in which the dCTP had been partially or completely replaced by its N4-methylated analog, N4-methyl-2'-deoxycytidine 5'-triphosphate (N4me-dCTP). In the case of a particularly GC-rich region (78.9% GC), the PCR mixtures containing N4me-dCTP produced the expected amplicon in high yield, while mixtures containing the canonical set of nucleotides produced numerous alternative amplicons. For another GC-rich DNA region (80.6% GC), the target amplicon was only generated by re-amplifying a gel-purified sample of the original amplicon with N4me-dCTP-containing PCR mixtures. In a direct PCR comparison on a highly GC-rich template, mixtures containing N4me-dCTP clearly performed better than did solutions containing the canonical set of nucleotides mixed with various organic additives (DMSO, betaine, or ethylene glycol) that have been reported to resolve or alleviate problems caused by secondary structures in the DNA. This nucleotide analog was also tested in PCR amplification of DNA regions with intermediate GC content, producing the expected amplicon in each case with a melting temperature (Tm) clearly below the Tm of the same amplicon synthesized exclusively with the canonical bases.
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Affiliation(s)
| | - Eva González-Jasso
- CICATA, Instituto Politécnico Nacional, Querétaro, Querétaro, 76090, Mexico
| | - Anaid Antaramian
- Instituto de Neurobiología, Universidad Nacional Autónoma de México, Juriquilla, Querétaro, 76230, Mexico
| | - Reynaldo C Pless
- CICATA, Instituto Politécnico Nacional, Querétaro, Querétaro, 76090, Mexico
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Flores-Juárez CR, Leberre Anton V, Trévisiol E, Antaramian A, González-Jasso E, Pless RC. Hybridisation of N4-methylcytosine-containing amplicons on DNA microarrays. J Biotechnol 2014; 189:143-9. [PMID: 25238723 DOI: 10.1016/j.jbiotec.2014.09.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2014] [Revised: 09/02/2014] [Accepted: 09/08/2014] [Indexed: 11/27/2022]
Abstract
5'-Cy5-labelled PCR amplicons containing the analogue base, N(4)-methylcytosine, instead of cytosines were compared in microarray hybridisation experiments with the corresponding amplicons containing the canonical set of bases, with respect to the intensity of the fluorescence signal obtained, and cross hybridisation to non-corresponding probes. In general, higher hybridisation temperatures resulted in reduced signal intensities, particularly in the case of the N(4)-methylcytosine containing amplicons. At the lower hybridisation temperatures tested (40 °C, 30 °C), these modified amplicons gave about equal or stronger fluorescence signal than the corresponding regular amplicons. With the two GC-richest amplicons tested, in one instance the N(4)-methylated target gave a dramatically higher signal intensity than the unmodified amplicon, interpreted as reflecting the reduced formation of hairpin structures in the target sequence, due to the lower thermodynamic stability of the G:N(4)-methylC base pair, making the target more accessible, while in the other case no hybridisation was observed with either version of the amplicon, probably due to interference from a G-tetrad structure. Both for the regular and the N(4)-methylated amplicons, no significant cross hybridisation was seen in these experiments.
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Affiliation(s)
| | - Véronique Leberre Anton
- Université de Toulouse, INSA, UPS, INP, LISBP, 135 Avenue de Rangueil, F-31077 Toulouse, France; INRA, UMR792, Ingénierie des Systèmes Biologiques et des Procédés, F-31400 Toulouse, France; CNRS, UMR5504, F-31400 Toulouse, France
| | - Emmanuelle Trévisiol
- Université de Toulouse, INSA, UPS, INP, LISBP, 135 Avenue de Rangueil, F-31077 Toulouse, France; INRA, UMR792, Ingénierie des Systèmes Biologiques et des Procédés, F-31400 Toulouse, France; CNRS, UMR5504, F-31400 Toulouse, France
| | - Anaid Antaramian
- Instituto de Neurobiología, Universidad Autónoma de México, Juriquilla, Querétaro 76230, Mexico
| | - Eva González-Jasso
- CICATA, Instituto Politécnico Nacional, Querétaro, Querétaro 76090, Mexico
| | - Reynaldo C Pless
- CICATA, Instituto Politécnico Nacional, Querétaro, Querétaro 76090, Mexico.
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