AUG 09, 2018 5:50 PM PDT

Observing Development at the Cellular Level

WRITTEN BY: Carmen Leitch

As the tools that scientists use to see cells and the structures inside of them have improved, our understanding of biological function has advanced. There are still limitations, however, and engineers are continuing to work to make microscopy techniques even better. Often, to see what’s happening in a cell, it must be fixed in place and studied after it has been preserved, but is no longer alive. Now researchers have created a method to see tiny things inside of live cells so that the dynamic events within can be viewed as they happen.

Deuterium is added to newly made proteins, lipids and DNA. The light of an SRS microscope illuminated each of the macromolecules. / Credit: Wei Min lab/Columbia University

This technique, reported in Nature Communications, uses a chemical tracer that is already in wide use - heavy water or D2O. It's been combined with stimulated Raman scattering (SRS), a laser-imaging tool that was developed relatively recently. It may not only be useful in the lab; it could also help surgeons remove tiny bits of tumors.

"We can use this technology to visualize metabolic activities in a wide range of animals," said  Wei Min, a chemistry professor at Columbia University and senior author of this study. "By tracking where and when new proteins, lipids, and DNA molecules are made, we can learn more about how animals develop and age, and what goes wrong in the case of injury and disease."

The water molecule has two hydrogen atoms and an oxygen atom; heavy water is made by using deuterium in place of the hydrogen. Anything under five tablespoons is not dangerous to humans, and cells will incorporate it into proteins, lipids and DNA they’re making.

Deuterium and carbon form a bond that vibrates at different frequencies when hit with light so that the various cellular molecules can be identified. The frequency signature a molecule emits allows it to be tracked through the cell. This labeling method is already used for molecules that are extracted, but this puts it into live cells.

Deuterium-labeled SRS imaging highlights brain cells in developing mice rapidly put on fat during myelination. Detecting abnormal myelination could head injury and multiple sclerosis diagnostics/. Credit: Min lab/Columbia

"We get a continuous picture of what's happening inside living animal cells. Previously, we had only a snapshot," said the co-lead author of the work, Lingyan Shi, a postdoctoral researcher at Columbia.

With this tool, the investigators watched the heavy metal get incorporation into parts of zebrafish, mice, and roundworms. They tracked fat production in the reproductive system of the roundworm as it aged. They observed the formation of a critical neuronal insulator called the myelin sheath in developing mouse brains, and other developmental events.

"The beauty of this mapping method is its simplicity," added Eric Potma, a chemistry professor at the University of California at Irvine who was not involved in the study. "It produces vivid images of metabolic activity in tissues with seemingly minimal effort. As the SRS microscope continues to get smaller, deuterium-labeled SRS imaging may help to catch tumors at much earlier stages."

Sweat glands cell turnover gradually pushes older cells are to the center of the glands, expelling them from the body. Here, cells at the outer edges of the mouse sweat glands (upper left and lower right) appear bright green, reflecting new lipid growth. Older cells in an interior sweat gland (lower left) have far less new lipid growth. (Wei Min lab/Columbia University)


Sources: AAAS/Eurekalert! Via Columbia University, Nature Communications

About the Author
  • Experienced research scientist and technical expert with authorships on over 30 peer-reviewed publications, traveler to over 70 countries, published photographer and internationally-exhibited painter, volunteer trained in disaster-response, CPR and DV counseling.
You May Also Like
SEP 09, 2020
Cell & Molecular Biology
Why Liver Gene Therapies Have Not Worked & How to Improve Them
SEP 09, 2020
Why Liver Gene Therapies Have Not Worked & How to Improve Them
Diseases that are caused by errors in a gene might be cured if we could correct those errors, or genetic mutations.
SEP 15, 2020
Cell & Molecular Biology
Autism Spectrum Disorder Biomarker is Discovered
SEP 15, 2020
Autism Spectrum Disorder Biomarker is Discovered
Scientists may have identified a biomarker for autism spectrum disorder, which can be difficult to differentiate from ot ...
SEP 25, 2020
Cell & Molecular Biology
Researchers Take Organoids a Step Further
SEP 25, 2020
Researchers Take Organoids a Step Further
The human body is made of many different kinds of cells, which can often be cultured in a lab and studied. However, thos ...
OCT 13, 2020
Clinical & Molecular DX
Test for Diabetes Checks If the Liver Is Responding
OCT 13, 2020
Test for Diabetes Checks If the Liver Is Responding
Glucagon is a hormone that prevents blood glucose levels from dropping too low by stimulating the liver to convert store ...
NOV 01, 2020
Cell & Molecular Biology
There's More to Neutrophil Function Than We Knew
NOV 01, 2020
There's More to Neutrophil Function Than We Knew
Neutrophils are an abundant type of white blood cell that circulate in the blood that can provide a general defense aga ...
NOV 25, 2020
Cell & Molecular Biology
Antibacterial Soap Ingredient May Increase Risk of Liver Disease
NOV 25, 2020
Antibacterial Soap Ingredient May Increase Risk of Liver Disease
The triclosan once commonly added to soap was banned by the FDA a few years ago, but it can still be found in some water ...
Loading Comments...