• Scientists turn cells into lasers

    Malte Gather / Nature Photonics

    A human kidney cell produces green laser light inside a resonator.

    By Nidhi Subbaraman

    Physicists and molecular biologists have created the world's first biological laser, with live, glowing kidney cells at its core.

    At the heart of a laser is a substance that can absorb, amplify and emit light in a single focused beam. This role has been played by a string of characters over the years: semiconductors, crystals, dyes and even gases. Until now, living cells weren't part of that cast lineup. There's a good reason for that: Most living things, with the exception of some bioluminescent jellyfish, don't naturally trap or emit light.

    But recently, other organisms have acquired the ability to shine. The researchers behind these glow-in-the-dark animals owe their thanks to Osamu Shimomura, who extracted the green fluorescence protein and the genes that make GFP from the glowing guts of those jellyfish. (Coincidentally, he started work on the bioluminescent crystal jellyfish in 1960 — the same year that the laser was invented.) 

    Since then, molecular biologists have gone gaga over the GFP gene and other fluorescence genes. They use them as visual signals indicating that the other genes they study have been successfully transferred into different organisms (such as cats and dogs). The ever-expanding popularity of fluorescence genes among molecular biologists earned its discoverers a shiny Nobel in 2008. Now the GFP gene itself is stealing the spotlight.

    "Almost any organism, from bacteria to higher mammalians, can be programmed to synthesize such luminescent proteins, so we wondered if GFP could be used to amplify light and build biological lasers," Malte Gather and Seok Hyun Yun, the two physicists behind the "biolaser," wrote in a Q&A interview with Nature Photonics. The journal published their paper online on Sunday.  

    Guiliano Scarcelli

    Malte Gather and Seok Hyun Yun are the inventors of the biological laser.

    The researchers reprogrammed a line of human embryonic kidney cells with an enhanced version of the GFP gene. Then they sandwiched those cells between highly reflective mirrors and pulsed a blue light through the chamber.

    In their optically active compartment, the cells absorbed and re-emitted a laser-worthy green light for several minutes. The mirrors amplified the light to create a coherent beam, just as they do in non-biological lasers.

    The cells survived for a few hours after the lasing ordeal, and seemed to be actively producing and reabsorbing the green fluorescence protein. This could mean that, unlike regular lasers which wear out with use, "the laser can self-heal," they told Nature Photonics.

    The two physicists are now working on ways to tweak the setup so that it can be used as a living imaging tool. Such lasers may shed new light, so to speak, on biological processes within the cell, Gather told me: "The pattern of the laser light seems to carry information about the insides of the cell."

    Biolasers could also have medical applications. Some treatments, such as photodynamic therapy for cancer patients, use external lasers to stimulate drugs to be released close to a tumor. "You have a drug that attacks a tumor when you apply light," Gather said. "Using a laser light force from the inside would make this more efficient."

    Ultimately, the researchers want to free the lasing cell from its optical chamber, and somehow include tiny reflective mirrors within the cell itself. "For medical applications, that would be crucial," Gather said.  

    More on lasers:

    Nidhi Subbaraman is the science and tech news intern at msnbc.com. Find Nidhi on Twitter, and connect with the Cosmic Log on Facebook. 

  • The wonders of the cell go online

    Linda Parysek via The Cell

    This photomicrograph showing mitochondria in a mouse cell is part of an online image database launched today.

    By John Roach, Contributing Writer, NBC News

    For many of us, the wonders of cell biology came alive when we peered through a microscope at an amoeba in science class. Today, a new online image library of cells brings that same sense of wonder and magic to anyone with an Internet connection.

    The library contains more than 1,000 images, videos, and animations of cells from a variety of organisms — from the Chinese hamster (Cricetulus griseus) to humans (Homo sapiens).

    The database aims to advance research on cellular activity with the ultimate goal of improving human health, according to the American Society for Cell Biology, which has created the database in partnership with Glencoe Software and the Open Microscopy Environment.

    "In our research of disease, one of the key features is to understand the mechanism of disease — and that is going to happen, in many cases, at the cellular level," David Orloff, manager of The Cell image library, told me.

    For example, the library will make it possible for scientists to compare different cell types online and understand the nature of specific cells and cellular processes, both normal and abnormal. This may lead to new discoveries about diseases, as well as new targets for drug development.

    T. Anderson, D. Benson via The Cell

    This image of a rat neuron highlights concentrations of a protein called N-cadherin (shown in red) as well as key chemical receptors (shown in green and blue).

    "By looking at our database of cells, a scientist could get information that can confirm or refute a hypothesis or even develop a new hypothesis," project principal investigator Caroline Kane, a professor emeritus of molecular and cell biology at the University of California at Berkeley, told the journal Clinical and Translational Science.

    On another level, Orloff told me that the database could serve as a tool to teach the basics of disease: "If someone puts an image of cancer cells dividing [in the library] and you can watch a cancer cell and its division and growth into a tumor versus a normal cell's growth, there's going to be an awareness for the researcher."

    The database serves as a publicly accessible educational resource for anyone interested in the wonders of cell biology. Think of it as science class without the stress of a pending exam — alhough students may want to study up anyway. "I've talked with a number of teachers who are very excited to have something like this to present in their classrooms," Orloff said.

    Development of The Cell was funded by a $2.5 million grant made available under the American Recovery and Reinvestment Act of 2009. In other words, this is stimulus money at work "to serve the public in an effort to cure disease ultimately — and advance scientific research," Orloff noted.

    More stories on cell biology:

    John Roach is a contributing writer for msnbc.com. Connect with the Cosmic Log community by hitting the "like" button on the Cosmic Log Facebook page or following msnbc.com's science editor, Alan Boyle, on Twitter (@b0yle).