Archive for July 2014
A living light bulb, ultrasensitive biodetection made easy
Correspondence: Xiaohu Gao xgao@uw.edu
Department of Bioengineering, University of Washington, Seattle, WA 98195, USA
Cell & Bioscience 2014, 4:34 doi:10.1186/2045-3701-4-34
Commentary
Semiconductor nanocrystals, commonly known as quantum dots (QDs), represent a new class of nanoprobes greatly advancing and expanding the capabilities of fluorescence imaging because of their superior electrical, optical, and structural properties compared to conventional fluorophores, such as size-tunable emission color, narrow and symmetrical emission peak, large absorption coefficient throughout a wide spectrum, outstanding brightness and photostability, and extremely large Stokes shift [1,2]. Furthermore, multicolor QDs can also serve as dopants in microspheres and nanospheres for optical barcoding and imaging signal amplification [3,4].
Highly fluorescent and monodisperse QDs are often chemically synthesized via high-temperature organometallic procedure [5]. Recently, Dr. Pang’s group at Wuhan University, China, has developed a very interesting approach by taming yeast cells into a living QD synthesizer [6]. Coupling yeasts’ natural intracellular metabolic reaction of Na2SeO3 and detoxification of Cd ions, highly fluorescent CdSe QDs can be made with precisely controlled sizes and emission wavelengths. Regardless of the preparation procedure, however, the as synthesized QDs are subject to complex multistep processing, such as isolation, purification, functionalization with surface ligands, and conjugation with biomolecules (e.g., antibodies), before downstream bio-imaging and -detection applications can be realized.
To address this problem, in a recent publication in ACS Nano [7], Pang’s group further advanced the microbial QD synthesizer using S. aureus cells, which can simultaneously produce highly fluorescent QDs inside and display Protein A on the cell surface. As a result, the whole bacterial cell is transformed into an ultrabright cellular beacon, with broad applications in ultrasensitive detection. Using pathogen detection as an example, they show detection sensitivity as low as 8.94 ng/mL (based on protein content).
The easy and sensitive detection is enabled by two key innovations. First, the application of whole cells as a fluorescent reporter eliminates the procedures for QD isolation and functionalization, which significantly simplifies assay preparation, Furthermore, the sandwich assay used in this paper maximizes the detection sensitivity by integrating the target enrichment capability of magnetic beads and signal amplification of cellular beacons [8].
Second, the protein A on S. aureus surface makes antibody conjugation easy. Through a simple mixing and incubation step, a variety of antibodies can be immobilized on the probe surface, enabling a broad application of the cellular beacon. It has been shown recently that although noncovalent, protein A - antibody binding is stable for at least a few hours [9,10], which is sufficient for most bio-detection assays.
In summary, the technology reported in this paper transforms cells into living light bulbs that can specifically highlight biological targets. The innovation and simplicity of this technology will stimulate further research on the use of live organisms for a wide spectrum of biomedical applications.
The electronic version of this article is the complete one and can be found online at: http://www.cellandbioscience.com/content/4/1/34
Image Source: http://www.theguardian.com/science/small-world/2013/aug/13/mother-nature-quantum-dots
Department of Bioengineering, University of Washington, Seattle, WA 98195, USA
Cell & Bioscience 2014, 4:34 doi:10.1186/2045-3701-4-34
Commentary
Semiconductor nanocrystals, commonly known as quantum dots (QDs), represent a new class of nanoprobes greatly advancing and expanding the capabilities of fluorescence imaging because of their superior electrical, optical, and structural properties compared to conventional fluorophores, such as size-tunable emission color, narrow and symmetrical emission peak, large absorption coefficient throughout a wide spectrum, outstanding brightness and photostability, and extremely large Stokes shift [1,2]. Furthermore, multicolor QDs can also serve as dopants in microspheres and nanospheres for optical barcoding and imaging signal amplification [3,4].
Highly fluorescent and monodisperse QDs are often chemically synthesized via high-temperature organometallic procedure [5]. Recently, Dr. Pang’s group at Wuhan University, China, has developed a very interesting approach by taming yeast cells into a living QD synthesizer [6]. Coupling yeasts’ natural intracellular metabolic reaction of Na2SeO3 and detoxification of Cd ions, highly fluorescent CdSe QDs can be made with precisely controlled sizes and emission wavelengths. Regardless of the preparation procedure, however, the as synthesized QDs are subject to complex multistep processing, such as isolation, purification, functionalization with surface ligands, and conjugation with biomolecules (e.g., antibodies), before downstream bio-imaging and -detection applications can be realized.
To address this problem, in a recent publication in ACS Nano [7], Pang’s group further advanced the microbial QD synthesizer using S. aureus cells, which can simultaneously produce highly fluorescent QDs inside and display Protein A on the cell surface. As a result, the whole bacterial cell is transformed into an ultrabright cellular beacon, with broad applications in ultrasensitive detection. Using pathogen detection as an example, they show detection sensitivity as low as 8.94 ng/mL (based on protein content).
The easy and sensitive detection is enabled by two key innovations. First, the application of whole cells as a fluorescent reporter eliminates the procedures for QD isolation and functionalization, which significantly simplifies assay preparation, Furthermore, the sandwich assay used in this paper maximizes the detection sensitivity by integrating the target enrichment capability of magnetic beads and signal amplification of cellular beacons [8].
Second, the protein A on S. aureus surface makes antibody conjugation easy. Through a simple mixing and incubation step, a variety of antibodies can be immobilized on the probe surface, enabling a broad application of the cellular beacon. It has been shown recently that although noncovalent, protein A - antibody binding is stable for at least a few hours [9,10], which is sufficient for most bio-detection assays.
In summary, the technology reported in this paper transforms cells into living light bulbs that can specifically highlight biological targets. The innovation and simplicity of this technology will stimulate further research on the use of live organisms for a wide spectrum of biomedical applications.
The electronic version of this article is the complete one and can be found online at: http://www.cellandbioscience.com/content/4/1/34
Image Source: http://www.theguardian.com/science/small-world/2013/aug/13/mother-nature-quantum-dots
AIDS researchers among dead in Malaysia Airlines Flight MH17 crash were en route to Australian conference
It is hard to believe. RIP
========================
Joep Lange was traveling from the Netherlands for the International AIDS Society's 20th annual conference in Melbourne, Australia. Also killed was World Health Organization spokesman Glenn Thomas, friends and colleagues say.
Complete report: http://www.nydailynews.com/life-style/health/aids-researchers-dead-malaysia-airlines-flight-mh17-crash-article-1.1871450
More about Prof. Joep Lange:
image source: www.caribcas.org
Tag :
general,
Disclose the Secret of Taipei 101 - Tuned Mass Damper & Startbucks
I visited Taipei 101 early this year. It has been remained to be the landmark in Taipei since 2004.
The most attractive feature I found was the "Tuned Mass Damper" - a 18-foot diameter, 728-ton steel sphere at 88th floors of the skyscraper. This is the only TMD open to public.
How at TMD works @ Youtube:
More about Tuned Mass Dampers:
如何幫大樓抗風防震？淺談台北101大樓阻尼器(1/2) (Chinese, NTU )
Back to my 101 journey, I observed that not much visitors interested how the TMD worked - no one read the poster for its background but keep photo taking. It is also funny to see how the tourists reacted during earthquake. Take a look on the following Taiwan news:
Beside TMD, of course, Startbucks at 35F is also another secret!
image source: http://cpmah2013.tust.edu.tw/c2013a043/page-5.htm
MIT Neuroscientists - Control Your Muscle Movement by Light / Optogenetics
This is a recent news from MIT - Controlling movement with light
Just a quick question comes to my mind, how accurate we can control a light beam to shine on a single cell? I am not an expert in controlling light. But I believe we can paralyze ourselves with a laser gun in the future, like those in the movies and cartoons.
To understand more about optogenetics, watch this video from MIT from Youtube.
Explained: Optogenetics
image source: http://newsoffice.mit.edu/
Possible mechanism and clinical potentials of allostery
Corresponding author: Peixin Huang huang.peixin@zs-hospital.sh.cn
Liver Cancer Institute, Pulmonary Department, Fudan University Zhongshan
Hospital, Shanghai 200032, China
Clinical and Translational Medicine 2014, 3:18 doi:10.1186/2001-1326-3-18
Abstract
Allostery is involved in the dynamic regulation of biological functions in proteins. Advances in allostery research have recently drawn great interest and brought allostery closer to the clinic. The present commentary describes the mechanism by which allostery may involve in from a cell-wide view and its contribution to the discovery of new therapeutics to diseases.
Background
Allostery is a universal phenomenon whereby an effector molecule combining with a (allosteric) site on the protein surface leads to a functional change through alteration of shape and/or dynamics, to regulate protein activity. Effector perturbations can result from a wide range of biological and physical phenomena, including the binding of a small effector molecule, post-translational modifications, protein binding, temperature changes, and pH changes. Allostery takes place in all dynamic proteins, single chains, and in RNA and DNA polymers.
The electronic version of this article is the complete one and can be found online at: http://www.clintransmed.com/content/3/1/18
Image source: Bahar Lab
Hospital, Shanghai 200032, China
Clinical and Translational Medicine 2014, 3:18 doi:10.1186/2001-1326-3-18
Abstract
Allostery is involved in the dynamic regulation of biological functions in proteins. Advances in allostery research have recently drawn great interest and brought allostery closer to the clinic. The present commentary describes the mechanism by which allostery may involve in from a cell-wide view and its contribution to the discovery of new therapeutics to diseases.
Background
Allostery is a universal phenomenon whereby an effector molecule combining with a (allosteric) site on the protein surface leads to a functional change through alteration of shape and/or dynamics, to regulate protein activity. Effector perturbations can result from a wide range of biological and physical phenomena, including the binding of a small effector molecule, post-translational modifications, protein binding, temperature changes, and pH changes. Allostery takes place in all dynamic proteins, single chains, and in RNA and DNA polymers.
The electronic version of this article is the complete one and can be found online at: http://www.clintransmed.com/content/3/1/18
Image source: Bahar Lab
Congratulation: The 4th Annual HKUST One Million Dollar Entrepreneurship Competition
The 4th Annual HKUST One Million Dollar Entrepreneurship Competition was held successfully. Congratulation to all winners and I wish all teams will fully utilize the experience they gained in the process and realize the business plan they presented!
Image source: onemilliondollar.ust.hk
The winners are: m-Care Technology Limited, SonoSolution Limited, Silicool.
For details: onemilliondollar.ust.hk
Image source: onemilliondollar.ust.hk
Why: Scientists threaten to boycott €1.2bn Human Brain Project
There is a controversial topic within neuroscience community in Europe about the HUMAN BRAIN PROJECT, www.humanbrainproject.eu, which was introduced by European commission with Euro 1.2 billion. Cool!! Euro 1.2 billion is huge amount of money and every researcher will fight for it of course. Nevertheless, it was reported that more than 100 leading scientists claimed to boycott this project. What they are arguing for?
"The changes sidelined cognitive scientists who study high-level brain functions, such as thought and behaviour. Without them, the brain simulation will be built from the bottom up, drawing on more fundamental science, such as studies of individual neurons."
"The rationale of the Human Brain Project is a plan for data: what do we do with all this data? This is a very exciting ICT project that will bring completely new tools and capabilities to all of neuroscience"
Read this article for details:
Scientists threaten to boycott €1.2bn Human Brain Project
This remind me the HUMAN GENOME PROJECT. It was a very successfully project in the past and brought both science and technology to a much higher level in nucleic acids studies. Those new technologies developed are now widely being applied in biolabs and bloom the research in the field. Can Human Brain Project follows a similar model? Why not?
image source: www.humanbrainproject.eu
"The changes sidelined cognitive scientists who study high-level brain functions, such as thought and behaviour. Without them, the brain simulation will be built from the bottom up, drawing on more fundamental science, such as studies of individual neurons."
"The rationale of the Human Brain Project is a plan for data: what do we do with all this data? This is a very exciting ICT project that will bring completely new tools and capabilities to all of neuroscience"
Read this article for details:
Scientists threaten to boycott €1.2bn Human Brain Project
This remind me the HUMAN GENOME PROJECT. It was a very successfully project in the past and brought both science and technology to a much higher level in nucleic acids studies. Those new technologies developed are now widely being applied in biolabs and bloom the research in the field. Can Human Brain Project follows a similar model? Why not?
image source: www.humanbrainproject.eu
Tag :
Human Brain Project,
science,
Gender Equality at university and Ms.Haruko Obokata
I follow the blog of Prof. Joseph Sung, the current President of CUHK. Recently, I read his post about gender equality which brings the topic of female academics again to the public. Here is the complete blog post:
(http://www.vco.cuhk.edu.hk/js_blog/index.php?option=com_jaggyblog&task=viewpost&id=79&lang=en-GB)
On the other hand, there is an article on New York times today with an eye catching title: Academic Scandal Shakes Japan, which discloses the story of Ms Haruko Obokata, a female scientist in RIKEN.
In the report, you will be really sad to find out how Japans' news media "packaged" a rising academic star. I am doubt how this behavior helps to promote the participation of woman in R&D in Japan. Hope this is not happen in your school and university.
image source: http://www.nytimes.com/
(http://www.vco.cuhk.edu.hk/js_blog/index.php?option=com_jaggyblog&task=viewpost&id=79&lang=en-GB)
On the other hand, there is an article on New York times today with an eye catching title: Academic Scandal Shakes Japan, which discloses the story of Ms Haruko Obokata, a female scientist in RIKEN.
In the report, you will be really sad to find out how Japans' news media "packaged" a rising academic star. I am doubt how this behavior helps to promote the participation of woman in R&D in Japan. Hope this is not happen in your school and university.
image source: http://www.nytimes.com/
Tag :
general,
What will be the INNOVATIONS around you in 2025? See what Thomson Reuters predicts ...
Define a good topic for your PhD study is a painful process, but extremely important. Your interest, fund availability, current research trends, your supervisor, etc.... all need to be considered.
Take a look on what Thomson Reuters predicts, let's see if you can find any idea there, or package your ideas well for your weekly meeting. Most of them are the current hot research topics and I find how new materials can check the world in the future.
1. Teleportation is Tested
2. DNA Mapping At Birth is the Norm to Avoid Disease Risk
3. Cancer Treatments Have Very Few Toxic Side Effects
4. Petroleum-Based Packaging Is History; Cellulose-Derived Packaging Rules
5. Digital Everything…Everywhere
6. Electric Air Transportation Takes Off
7. Solar is the Largest Source of Energy on the Planet
8. Food Shortages and Food Price Fluctuations Are Things of the Past
9. Type 1 Diabetes is Preventable
10. Dementia Declines
image source: Thomson Reuters, www.theguardian.com
Tag :
general,
Thomson Reuters,
Stephanie Kwolek invented a super strong polymer for your tires and sports equipment
Current issue of ACS Weekly Newletter reported the death of Stephanie L.Kwolek, a 90 years old chemist who invented the a super strong polymer, Kevlar, widely used in bulletproof vests, tires, sports equipment, and optical fiber.
“She leaves a wonderful legacy of thousands of lives saved and countless injuries prevented by products made possible by her discovery.” by DuPont Chief Executive Officer Ellen J. Kullman.
Here is the complete article: Stephanie Kwolek Dies At 90
More:
@ RSC: Chemistry in its element - Kevlar
@ DuPont: Better, Stronger and Safer with Kevlar® Fiber
@ Engineering.com: Kevlar(R)
@ Bodyarmornews.com: How does armor work?
image source: DoPont.com