scholarly journals Dual UMIs and Dual Barcodes With Minimal PCR Amplification Removes Artifacts and Acquires Accurate Antibody Repertoire

2021 ◽  
Vol 12 ◽  
Author(s):  
Qilong Wang ◽  
Huikun Zeng ◽  
Yan Zhu ◽  
Minhui Wang ◽  
Yanfang Zhang ◽  
...  

Antibody repertoire sequencing (Rep-seq) has been widely used to reveal repertoire dynamics and to interrogate antibodies of interest at single nucleotide-level resolution. However, polymerase chain reaction (PCR) amplification introduces extensive artifacts including chimeras and nucleotide errors, leading to false discovery of antibodies and incorrect assessment of somatic hypermutations (SHMs) which subsequently mislead downstream investigations. Here, a novel approach named DUMPArts, which improves the accuracy of antibody repertoires by labeling each sample with dual barcodes and each molecule with dual unique molecular identifiers (UMIs) via minimal PCR amplification to remove artifacts, is developed. Tested by ultra-deep Rep-seq data, DUMPArts removed inter-sample chimeras, which cause artifactual shared clones and constitute approximately 15% of reads in the library, as well as intra-sample chimeras with erroneous SHMs and constituting approximately 20% of the reads, and corrected base errors and amplification biases by consensus building. The removal of these artifacts will provide an accurate assessment of antibody repertoires and benefit related studies, especially mAb discovery and antibody-guided vaccine design.

1996 ◽  
Vol 44 (10) ◽  
pp. 1205-1207 ◽  
Author(s):  
A Dakhama ◽  
V Macek ◽  
J C Hogg ◽  
R G Hegele

The polymerase chain reaction (PCR) is a powerful method that allows enzymatic amplification of rate target nucleic acid sequences. It has been applied to the amplification of viral genomes from paraffin-embedded pathology specimens. However, interpretation of negative results requires amplification of a housekeeping gene such as beta-actin. In the present study we used specific oligonucleotide primers previously designed to amplify both the genomic DNA and the mRNA transcript from paraffin-embedded tissue. These products have predicted sizes of 250 BP and 154 BP, respectively, but our results showed that PCR amplification only (without reverse transcription) unexpectedly generated the 154-BP product. Further investigation of the nature of this product demonstrated that it originated from the amplification of DNA, not RNA. We conclude that the 154-BP product generated by these primers cannot be exclusively considered as beta-actin RNA product and should not be used to assess successful extraction of RNA, to ascertain its integrity, or to normalize for the total amount of RNA assayed by RT-PCR from paraffin-embedded tissue.


2011 ◽  
Vol 27 (3) ◽  
pp. 357-364
Author(s):  
B. T. Chia ◽  
S.-A. Yang ◽  
M.-Y. Cheng ◽  
C.-W. Lin ◽  
Y.-J. Yang

ABSTRACTIn this paper, the development of a portable polymerase chain reaction (PCR) device is presented. Integrating electromagnetic mini-actuators for bi-directional fluid transport, the proposed device, whose dimension is 67mm × 66mm × 25mm, can be fully operated with a 5V DC voltage. The device consists of four major parts: A disposable channel chip in which PCR mixture is manipulated and reacted, a heater chip which generates different temperature zones for PCR reaction, a linear actuator array for pumping PCR mixture, and a circuit module for controlling and driving the system. The advantages of the device include the rapid temperature responses associated with continuous-flow-type PCR devices, as well as the programmable thermal cycling associated with chamber-type PCR devices. The thermal characteristics are measured and discussed. PCR amplification is successfully performed for the 122 bp segment of MCF-7/adr cell line. Due to its small footprint, this self-contained system potentially can be employed for point-of-care (POC) applications.


2012 ◽  
Vol 49 (2) ◽  
pp. 67-70 ◽  
Author(s):  
M. Kolesárová ◽  
R. Herich ◽  
M. Levkut ◽  
J. Čurlík ◽  
M. Levkut

AbstractPCR amplification of specific DNA regions is a powerful tool for retrospective studies, but not all preservation or fixation methods render DNA that is suitable for subsequent amplification. Several factors affect sensitivity of polymerase chain reaction (PCR) amplification. There were reported the effects of commonly used fixation solutions — 10 % neutral buffered formalin, 20 % neutral buffered formalin and Carnoy’s solution and the efficiency of PCR amplification in fresh tissue and paraffin (or wax) embedded samples of Cysticercus ovis. DNA from samples was isolated and PCR product of 1300 bp was amplified. Results indicated that the samples fixed in Carnoy’s solution produced reliable amplification of desired fragments. The samples that were fixed in 10 % and 20 % neutral buffered formalin brought negative results.


Author(s):  
Dwiyitno Dwiyitno ◽  
Stefan Hoffman ◽  
Koen Parmentier ◽  
Chris Van Keer

Fish and seafood products has been commonly targeted for fraudulent activities. For that reason, authentication of fish and seafood products is important to protect consumers from fraudulent and adulteration practices, as well as to implement traceability regulation. From the viewpoint of food safety, authenticity is beneficial to protect public from serious food poisoning incidents, such as due to ingestion of toxic species. Since DNA based identification depends on the nucleic acid polymerase chain reaction (PCR), the quantity and quality/purity of DNA will contribute significantly to the species authentication. In the present study, different DNA extraction and purification methods (3 classical methods and one commercial kit) were compared to produce the better isolated DNA for PCR amplification. Additionally, different methods for the estimation of DNA concentration and purity which is essential for PCR amplification efficiency were also evaluated. The result showed that classical DNA extraction methods (based on TNES-Urea) yielded a higher amount of DNA (11.30-323.60 ng/g tissue) in comparison to commercial kit/Wizard Promega (5.70-83.45 ng/g tissue). Based on the purity of DNA extract (A260/280), classical DNA extraction method produced relatively similar on DNA quality to the commercial kit (1.79-2.12). Interestingly, all classical methods produced DNA with A260/280 ratio of more than 2.00 on the blue mussel, in contrast with commercial kit. The commercial kit also produced better quality of DNA compared to the classical methods, showing the higher efficiency in PCR amplification. NanoDrop is promising as cheap, robust and safe UV-spectrophotometer method for DNA quantification, as well as the purity evaluation.Keywords: seafood authenticity, DNA isolation, polymerase chain reaction, NanoDrop, Picogreen


2019 ◽  
Vol 6 (2) ◽  
pp. 259
Author(s):  
Asep Gunawan ◽  
Ratna Sholatia Harahap ◽  
Kasita Listyarini ◽  
Cece Sumantri

ABSTRAK Karakteristik karkas dan sifat perlemakan pada daging domba dikontrol oleh banyak gen salah satunya gen DGAT1 (Diacylglycerol Acyltransferasel 1). Penelitian ini bertujuan mengidentifikasi SNP (Single Nucleotide Polymorphism) gen DGAT1 pada titik mutasi g.8539 C>T dan asosiasinya terhadap karakteristik karkas dan sifat perlemakan pada domba Indonesia. Total sampel domba yang digunakan sebanyak 150 buah terdiri dari 35 sampel domba compass agrinak (DCA), 36 sampel domba barbados cross (DBC), 41 sampel domba komposit garut (DKG), 20 sampel domba ekor gemuk (DEG), dan 18 sampel domba ekor tipis (DET). Karakteristik karkas dan sifat perlemakan diukur dari domba jantan berumur 10-12 bulan. Identifikasi keragaman DGAT1|ALuI dianalisis dengan metode PCR-RFLP (Polymerase Chain Reaction-Restriction Fragment Length Polymorphism). Hasil keragaman gen DGAT1 bersifat polimorfik dalam DET dan DEG, sedangkan DCA, DBC, dan DKG bersifat monomorfik. Dua genotipe disebut CC dan  CT ditemukan dalam DET dan DEG. Titik mutasi gen DGAT1 berasosiasi (P<0.05) dengan karakteristik karkas, yaitu bobot dan panjang karkas. Selain itu, keragaman gen DGAT1 juga berasosiasi signifikan (P<0.05) dengan asam lemak jenuh, yaitu asam stearat (C18:0) dan asam arakidat (C20:0) dan asam lemak tak jenuh tunggal, yaitu asam oleat (C18:1n9c). Gen DGAT1 memiliki kontribusi dalam karakteristik karkas dan komposisi asam lemak pada domba.Kata Kunci: domba, gen DGAT1, karakteristik karkas, PCR-RFLP, sifat perlemakan                                                              ABSTRACT            Characteristic of carcass and fatness traits of sheep is regulated by many genes such as DGAT1 (Diacylglycerol Acyltransferasel 1) gene. The research was aimed to investigate SNP (Single Nucleotide Polymorphism) of DGAT1 and its association with characteristic of carcass and fatness traits in Indonesian sheep. A total sample of sheeps used 150 rams of 10–12 months consisted 35 samples of compas agrinak sheep (CAS), 36 of barbados cross (BCS), 41 of garut composite (GCS), 20  of javanese fat tailed (JFT), and 18 of javanese thin tailed (JTT). Identification variant of DGAT1|ALuI were performed by PCR-RFLP (Polymerase Chain Reaction-Restriction Fragment Length Polymorphism). The results of polymorphism of DGAT1 were found in JTT and JFT. However, SNP of DGAT1 in CAS, BCS and GCS were monomorfic. Two genotype namely CC and CT were found in JTT and JFT populations. A SNP of the DGAT1 was associated (P<0.05) with characteristic of carcass, including weight and length of carcass. The variant of DGAT1 was associated too with saturated fatty acids (SFA) including stearic acid (C18:0) and arachidic acid (C20:0), and mono unsaturated fatty acid (MUFA) including oleic acid (C18:1n9c). The DGAT1 gene was contribute to characteristic carcass and fatty acid composition in sheep.Keywords: DGAT1 gene, characteristic carcass, fatness traits, PCR-RFLP, sheep


2002 ◽  
Vol 50 (11) ◽  
pp. 3161-3164 ◽  
Author(s):  
Saad Masri ◽  
Heidi Rast ◽  
Teresa Ripley ◽  
Delano James ◽  
Margaret Green ◽  
...  

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