May 1, 2006 (Vol. 26, No. 9)
Susan Aldridge, Ph.D.
Technologies for Capturing Details in Small Organisms, Organs, Tissues, and Even Cells
The production and storage of high quality images of cells, tissues, and even whole organisms has never been more important. Olympus (www.olympus-europa.com) is responding to this challenge with a range of new microscope technologies with applications in areas, such as cell-based screening, whole organism gene expression studies in, for example, zebrafish, and the micromanipulations of cells.
The SZX2 series of stereomicroscopes offers high-resolution combined with high zoom ratio. “The stereo microscope is a workhorse in many labs,“ says Winfried Busch, Ph.D., product manager for life science microscopy. “But our customers wanted something new.“
High-Res, High Zoom Ratio
The SZX16 is a research instrument with a maximum numerical aperture of 0.3, which can produce a resolution of 900 line pairs/mm. It has full fluorescence capability, which enables researchers to extract the maximum information from experiments. “Fluorescence imaging is such an important technology, especially now that there are many new dyes on the market for the functional analysis of living species,“ says Dr. Busch.
“There is also a trend toward using this technology to understand the complete organism, rather than just one cell, which means stereo microscopes are being used even more.“
At 16.4:1, the SZX16 has the highest zoom ratio of any stereo microscope currently on the market, according to the company. This allows the user to go from whole organism to the cellular level and back with no major adjustments. It also has enhanced 3-D vision, which makes it good for micromanipulations of cells, such as microinjection.
Meanwhile, the SZX10 is for advanced routine applications, such as quality control and specimen identification. “The instrument is applicable where a natural view is needed, where morphological comparison might be wanted,“ explains Dr. Busch. A further feature of the SZX2 series is its use of light-emitting diodes as a cold light source, thus not heating up the specimen.
The SZX16 can also be used with the new infrared dyes that minimize the bleaching of the specimen. The SZX2 also carries a correction ring, which can compensate for the optical aberrations caused by the different refractive indices of air, petri dish cover, and water.
The MacroZoom range has been launched with the MVX10 MacroView microscope, which combines maximum detection sensitivity at the lowest magnification with a high magnification zoom feature for the resolution of fine detail within small organisms, organs, tissues, and even cells. The set up allows studies of gene expression, including weak gene expression, in a whole organism, such as zebrafish or C.elegans, when transformed with green fluorescent protein and also detailed observation of expression in cells at a higher magnification.
The single path optics of the MVX10 reportedly delivers brightness and resolution beyond the capabilities of a conventional fluorescence stereo microscope. So there is no longer a need to switch between a stereo microscope and a compound microscope in fluoresence screening experiments, the company asserts.
The MVX100 can, however, be switched to give a stereo view, which is good for dissection and manipulation of samples. “We are introducing the MacroZoom systems because the trend in research is to go from single cell studies to work on tissues and even whole organisms,“ explains Werner Kammerloher, Ph.D., product manager life science microscopy. “The important applications of these systems are likely to be in going from basic to translational work, such as real clinical diagnostics. Another significant trend is the increase in fluorescence analytical applications, especially using green and red fluorescent proteins and the near infrared dyes, which can allow you to look deeper into bigger organisms.“
Cameras to Record and Store Images
The Olympus microscopes can be interfaced with cameras and software for recording and storage of image information. The combination of the SZX2 stereo microscopes with the new DP71 cooled digital camera requires no extra optics and makes for a very flexible imaging system, the company says. The DP71 combines high sensitivity with fast image acquisition for both bright-field and fluorescence imaging.
This year should see the release of a related MacroZoom system, the QV100, which is an in vivo imaging system developed out of the MVX10 and designed for advanced whole mouse imaging from the macro- to the micro-scale—going from anatomy down to the cellular level. The QV100 reportedly will allow time-lapse and live imaging of emitted light, such as fluorescence, from labeled processes and tissues.