Nav: Home

Measuring forces of living cells and microorganisms

January 28, 2019

Forces that are exerted by a living cell or a microorganism are tiny and often not larger than a few nanonewtons. For comparison, one nanonewton is the weight of one part in a billion of a typical chocolate bar. Yet, for biological cells and microbes, these forces are enough to allow cells to stick to a surface or microbes to propel themselves towards nutrients. Scientists from Finland and Germany now present a highly adaptable technique, called 'micropipette force sensors', to precisely measure the forces exerted by a wide range of micron-sized organisms. This novel method has now been published in the highly ranked international journal Nature Protocols.

To stay alive and proliferate, a biological cell needs to be able to successfully adapt to its environmental conditions. The ability to do so involves physical principles and mechanical forces: cells may attach themselves to surfaces and other cells to eventually form a biofilm, a structure which protects the community of cells from external attack. Many microorganisms can actively move themselves, by crawling on a surface or swimming in liquid, for example, towards a source of nutrients. In order to advance our fundamental understanding of how microbes can move themselves, it's important for us to be able to measure the mechanical forces associated with their movement.

The development of micropipette force sensors to measure forces of living cells and microorganisms is described in a joint work by Dr. Matilda Backholm and Dr. Oliver Bäumchen. "The working principle of the micropipette force sensor technique is beautifully simple: by optically observing the deflection of a calibrated micropipette, the forces acting on the pipette can be directly measured", says Matilda Backholm, researcher at the Department of Applied Physics of Aalto University in Finland.

A micropipette is a hollow glass needle featuring a thickness of about the diameter of a human hair or even smaller. One of the most remarkable advantages of this technique is the fact that it can be applied to a large variety of biological systems, ranging from a single cell to a millimeter-size microorganism. "We exemplified the versatility of our method using two model systems from microbiology, but certainly the technique can and will be applied to other biological systems in the future", says Oliver Bäumchen, research group leader at the Max Planck Institute of Dynamics and Self-Organization in Göttingen, Germany.

"The idea behind the technique is to combine the advantages of several established biophysical techniques: we use a micropipette to grab a living cell, in the exact same way as it is done in in-vitro fertilization, and study the mechanical forces by measuring the pipette's deflection using the measurement principles underlying atomic force microscopy - a standard measurement technique in physics.", says Bäumchen. Dr. Backholm points out another major advantage: "In contrast to other force measurement methods, we detect the deflection of our highly sensitive micropipette simply by observing it with a state-of-the-art microscope. This allows us to inspect the shape and motion of the microorganism with high optical resolution, while we are measuring the forces simultaneously." During all of this, the cell or microorganism is fully intact and alive, which allows for testing its reaction to drugs as well as nutrients, temperature and other environmental factors. "The force resolution is really remarkable. With our recent technological advancements, we successfully managed to detect forces down to about ten piconewtons, which is almost as good as an atomic force microscope", adds Dr. Bäumchen.

The researchers expect that their method will be applied in other research labs in the future to tackle a plethora of important biophysical questions, aiming at better understanding biological functions of cells and microorganisms, as well as their underlying physical principles. Dr. Backholm points out that these research avenues may indeed advance biomedical and biotechnological applications: "The micropipette force sensor technique might help to identify drugs for fighting infectious diseases and inhibiting the formation of biofilms on medical implants, just to name a few examples where this novel approach might make a significant impact."
-end-


Aalto University

Related Microorganisms Articles:

Biochar provides high-definition electron pathways in soil
Cornell University scientists have discovered a new high-definition system that allows electrons to travel through soil farther and more efficiently than previously thought.
Microorganisms in the subsurface seabed on evolutionary standby
Through genetic mutations microorganisms normally have the ability to develop new properties over a short time scale.
Study tightens connection between intestinal microorganisms, diet, and colorectal cancer
A new study led by researchers at Dana-Farber Cancer Institute provides some of the strongest evidence to date that microorganisms living in the large intestine can serve as a link between diet and certain types of colorectal cancer.
Gut microorganisms affect our physiology
Researchers have found evidence that could shed new light on the complex community of trillions of microorganisms living in all our guts, and how they interact with our bodies.
The evolutionary secret of H. pylori to survive in the stomach
Professor Frédéric Veyrier's most recent research, in collaboration with the team of Professor Hilde De Reuse at the Institut Pasteur, has shed light on key genes essential to the pathogenesis of Helicobacter pylori bacterium, which causes gastric infections.
Compounds produced by phytopathogenic microbes encourage plant growth
A broad range of microorganisms, including phytopathogenic fungi and bacteria, are capable of producing volatile compounds that encourage plant growth, flowering and the accumulation of reserve substances.
Compounds emitted by phytopathogen microbes encourage plant growth
A wide range of microorganisms, including fungi and phytopathogenic bacteria, are capable of emitting volatile compounds which boost plant growth and flowering, and in accumulating up reserves as demonstrated in a study led by scientific researchers at Navarra's Institute of Agro biotechnology, in northern Spain, which is a mixed centre shared between Spain's National Research Council (CSIC), the Public University of Navarra, and the Regional Government of Navarra.
Which genes are crucial for the energy metabolism of Archaea?
A research team led by Christa Schleper from the University of Vienna succeeded in isolating the first ammonia-oxidizing archaeon from soil: Nitrososphaera viennensis -- the 'spherical ammonia oxidizer from Vienna.' In the current issue of the renowned journal PNAS, the scientists present new results: they were able to detect all proteins that are active during ammonia oxidation -- another important piece of the puzzle for the elucidation of the energy metabolism of Archaea.
WDCM released first Microbial Resource Development Report for China
The World Data Center for Microorganisms (WDCM) and Center for Microbial Resources and Big Data of the Institute of Microbiology of CAS (IMCAS) jointly released the '2016 Microbial Resource Development Report for China' on Sept.
Mass biofuel production without mass antibiotic use
Rather than applying mass amounts of antibiotics to vats of biofuel-producing microorganisms to keep control these cultures, researchers have developed a new technique using modified strains that outcompete other possible contaminating microbes.

Related Microorganisms Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Setbacks
Failure can feel lonely and final. But can we learn from failure, even reframe it, to feel more like a temporary setback? This hour, TED speakers on changing a crushing defeat into a stepping stone. Guests include entrepreneur Leticia Gasca, psychology professor Alison Ledgerwood, astronomer Phil Plait, former professional athlete Charly Haversat, and UPS training manager Jon Bowers.
Now Playing: Science for the People

#524 The Human Network
What does a network of humans look like and how does it work? How does information spread? How do decisions and opinions spread? What gets distorted as it moves through the network and why? This week we dig into the ins and outs of human networks with Matthew Jackson, Professor of Economics at Stanford University and author of the book "The Human Network: How Your Social Position Determines Your Power, Beliefs, and Behaviours".