Making live cell microscopy affordable

Jul 13, 2012
Figure 1: An image of fluorescently labeled unfertilized cow oocytes using the halogen lamp filter adapter. The nuclei are clearly observed at the center of the cells. Credit: Reproduced, in part, from Ref. 1 © 2012 K. Yamagata et al., RIKEN Center for Developmental Biology

Researchers in Japan have developed a low-intensity light source that allows cell biologists to visualize and handle live cells without destroying them during prolonged exposure. In addition to laying the foundation for new cell manipulations, the development will make advanced biology requiring fluorescence microscopy accessible to underfunded laboratories. Led by Teruhiko Wakayama from the RIKEN Center for Developmental Biology, Kobe, the researchers developed an adapter, equipped with a halogen lamp, for a conventional microscope.

Typically, conventional microscopes used in live cell studies rely on powerful ultraviolet (UV) lamps or lasers to illuminate cells labeled with a fluorescent . However, extended imaging times or continuous exposure to these high-intensity light sources results in harmful effects to cells. Although the problem seemed complex, Wakayama explains that simply lowering the strength of the via a halogen lamp solved the problem of phototoxicity.

The adapter developed by the researchers consisted of a small excitation filter and a diaphragm that allowed some light to leak around its periphery. They placed it on top of the microscope’s condenser lens, which concentrates light from the lamp onto the samples. By closing the diaphragm, they channeled all the light through the filter, yielding only fluorescence. Opening the produced a bright field image that merged with the fluorescent signal. The researchers found that they could tune the relative intensities of both images by varying this opening. 

Wakayama and his colleagues tested the performance of their device for monitoring the enucleation, or the removal of metaphase chromosomes, from female reproductive cells called oocytes. They discovered that, unlike traditional enucleation approaches, the new method allowed them to successfully remove the chromosomes in quantitative yields. This made it unnecessary to use additional analytical techniques to confirm the absence of chromosomes (Fig. 1). Overall, compared to conventional approaches, the halogen lamp method significantly simplified fluorescent observation of the enucleation procedure and reduced processing times without affecting cell viability.  

The team is currently planning to use their fluorescence imaging system to rapidly detect the fertilization of human oocytes. “Previously, we could not observe these oocytes using [owing] to UV lamp-induced cell damage, but now we can thanks to our adapter,” says Wakayama. Moreover, the researchers are proposing to introduce their device to high schools, which use simple that lack fluorescence imaging capabilities. “Our system will make it possible for all students to have access to advanced fluorescence microscopy without excessive costs,” he adds.

Explore further: Bacterial immune system has a better memory than expected

More information: Yamagata, K., et al. Fluorescence cell imaging and manipulation using conventional halogen lamp microscopy. PLoS ONE 7, e31638 (2012).

add to favorites email to friend print save as pdf

Related Stories

The Dye with the Pumpkin Cuff

Jun 20, 2005

Complexation with a large cuff-shaped molecule stabilizes rhodamine dye fluorescence When irradiated, fluorescent dyes emit light at a different wavelength; for scientists and engineers, these dyes are extremely important aide ...

Recommended for you

Researchers successfully clone adult human stem cells

14 hours ago

(Phys.org) —An international team of researchers, led by Robert Lanza, of Advanced Cell Technology, has announced that they have performed the first successful cloning of adult human skin cells into stem ...

Researchers develop new model of cellular movement

17 hours ago

(Phys.org) —Cell movement plays an important role in a host of biological functions from embryonic development to repairing wounded tissue. It also enables cancer cells to break free from their sites of ...

For resetting circadian rhythms, neural cooperation is key

Apr 17, 2014

Fruit flies are pretty predictable when it comes to scheduling their days, with peaks of activity at dawn and dusk and rest times in between. Now, researchers reporting in the Cell Press journal Cell Reports on April 17th h ...

User comments : 0

More news stories

Researchers successfully clone adult human stem cells

(Phys.org) —An international team of researchers, led by Robert Lanza, of Advanced Cell Technology, has announced that they have performed the first successful cloning of adult human skin cells into stem ...

Male monkey filmed caring for dying mate (w/ Video)

(Phys.org) —The incident was captured by Dr Bruna Bezerra and colleagues in the Atlantic Forest in the Northeast of Brazil.  Dr Bezerra is a Research Associate at the University of Bristol and a Professor ...

Researchers develop new model of cellular movement

(Phys.org) —Cell movement plays an important role in a host of biological functions from embryonic development to repairing wounded tissue. It also enables cancer cells to break free from their sites of ...

Impact glass stores biodata for millions of years

(Phys.org) —Bits of plant life encapsulated in molten glass by asteroid and comet impacts millions of years ago give geologists information about climate and life forms on the ancient Earth. Scientists ...