Analyst Blog

A height-dependent linear temperature gradient established on the inclined surface of a 3D qiandu (right triangular prism)-shaped PDMS microdevice enables flow-through PCR employing a single heater

South Korean scientists have created a temperature cycle for the on-chip flow-through polymerase chain reaction (PCR) using a single heater.

PCR is used to make copies of a piece of  DNA for genetic research, disease analysis and diagnosis. It consists of four main steps – initialisation; denaturation (melting the DNA template to yield single-stranded DNA); annealing primers to the single-stranded DNA template; and extension, in which the DNA polymerase synthesises a new DNA strand complementary to the DNA template.

On-chip flow-through PCR typically has a short reaction time due to rapid thermal equilibrium allowing quick temperature transitions; however, it normally requires several separate heating blocks to create the different temperatures. Reducing the number of heaters will help make the whole system smaller and more portable. ‘Analysing samples on site could help prevent degradation and contamination,’ explains Nae Yoon Lee from Gachon University, South Korea, who led the research.

Read the full story here in Chemistry World.

Link to journal article:

Flow-through PCR on a 3D qiandu-shaped polydimethylsiloxane (PDMS) microdevice employing a single heater: toward microscale multiplex PCR
Wenming Wu,  Kieu The Loan Trinh and Nae Yoon Lee
Analyst, 2012, Advance Article
DOI: 10.1039/C2AN35077G

It’s been a busy year already with so many great papers, so here are some HOT articles from Analyst that you might have missed this month!

Why not take a look, they will be free to read for 2 weeks.

A hydrophobic entrance enhances ion current rectification and induces dewetting in asymmetric nanopores
Matthew Pevarnik, Ken Healy, Matthew Davenport, Joseph Yen and Zuzanna S. Siwya
Analyst, 2012, Advance Article
DOI: 10.1039/C2AN16139G

Analytical investigation of salivary calculi, by mid-infrared spectroscopy
Jean-François Sabot, Marie-Paule Gustin, Katia Delahougue, Frédéric Faure, Christelle Machon and Daniel-Jean Hartmann
Analyst, 2012, Advance Article
DOI: 10.1039/C2AN15924D

Metal-based impurities in graphenes: application for electroanalysis
Sze Yin Chee and Martin Pumera
Analyst, 2012, Advance Article
DOI: 10.1039/C2AN00022A

Integration of gas chromatography mass spectrometry methods for differentiating ricin preparation methods
David S. Wunschel, Angela M. Melville, Christopher J. Ehrhardt, Heather A. Colburn, Kristin D. Victry, Kathryn C. Antolick, Jon H. Wahl and Karen L. Wahl
Analyst, 2012, Advance Article
DOI: 10.1039/C2AN16186A

A novel method for simultaneous analysis of three β2-agonists in foods with the use of a gold-nanoparticle modified glassy carbon electrode and chemometrics
Xiaoyun Lin, Yongnian Ni, Shuzhen Li and Serge Kokot
Analyst, 2012, Advance Article
DOI: 10.1039/C2AN16062E

Flow-through PCR on a 3D qiandu-shaped polydimethylsiloxane (PDMS) microdevice employing a single heater: toward microscale multiplex PCR
Wenming Wu, Kieu The Loan Trinh and Nae Yoon Lee
Analyst, 2012, Advance Article
DOI: 10.1039/C2AN35077G

Electrochemiluminescent detection of Mucin 1 protein and MCF-7 cancer cells based on the resonance energy transfer
W. Wei, D. F. Li, X. H. Pan and S. Q. Liu
Analyst, 2012, Advance Article
DOI: 10.1039/C2AN35059A

Enhanced fluorescent chemosensor for Ag+ in absolute aqueous solution and living cells: An experimental and theoretical study
Mingming Hu, Jiangli Fan, Jianfang Cao, Kedong Song, Hua Zhang, Shiguo Sun and Xiaojun Peng
Analyst, 2012, Advance Article
DOI: 10.1039/C2AN16272E

Ultrasensitive electrochemiluminescence immunosensor using PtAg@carbon nanocrystals composites as labels and carbon nanotubes-chitosan/gold nanoparticles as enhancer
Meng Zhang, Weijian Dai, Mei Yan, Shenguang Ge, Jinghua Yu, Xianrang Song and Wei Xu
Analyst, 2012, Advance Article
DOI: 10.1039/C2AN35186B

A new continuous fluorometric assay for acetylcholinesterase activity and inhibitor screening with emissive core–shell silica particles containing tetraphenylethylene fluorophore
Xiang Shen, Fuxin Liang, Guanxin Zhang and Deqing Zhang
Analyst, 2012, Advance Article
DOI: 10.1039/C2AN35154D

Examining changes in cellular communication in neuroendocrine cells after noble metal nanoparticle exposure
Sara A. Love, Zhen Liu and Christy L. Haynes
Analyst, 2012, Advance Article
DOI: 10.1039/C2AN00034B

Noise Adjusted Principal Component reconstruction to optimize infrared microspectroscopy of individual live cells
Ellen J. (Swain) Marcsisin, Christina M. Uttero, Antonella I. Mazur, Miloš Miljković, Benjamin Bird and Max Diem
Analyst, 2012, Advance Article
DOI: 10.1039/C2AN15868J

Graphene oxide integrated sensor for electrochemical monitoring of mitomycin C–DNA interaction
Arzum Erdem, Mihrican Muti, Pagona Papakonstantinou, Ece Canavar, Hakan Karadeniz, Gulsah Congur and Surbhi Sharma
Analyst, 2012, Advance Article
DOI: 10.1039/C2AN16011K

Expression of membrane-associated proteins within single emulsion cell fascimiles
Mayuree Chanasakulniyom, Chiara Martino, David Paterson, Louise Horsfall, Susan Rosser and Jonathan M. Cooper
Analyst, 2012, Advance Article
DOI: 10.1039/C2AN35047E

In this HOT article Xiu-Ping Yan and colleagues from Nankai University have developed a colourimetric method to determine the presence of histidine in urine. The method is detectable by the naked-eye, with an obvious colour change from yellow to purple. The detection of histidine, an amino acid found in many proteins, is used to help with the diagnosis of histidine metabolism disorders and other diseases such as epilepsy and Parkinson’s disease.

Yan et al., Analyst, 2012, Advance Article

Take a look at their paper, it will be free to read for 2 weeks.

An indicator-displacement assay for naked-eye detection and quantification of histidine in human urine
Shao-Kai Sun, Kai-Xiong Tu and Xiu-Ping Yan
Analyst, 2012, Advance Article
DOI: 10.1039/C2AN35126A