Wavelength Tech Forum: Fluorescence

This month’s Technology Forum looks at the topic of Fluorescence and the trends and issues surrounding it. Joining us for this discussion are Luis A. Moreno, Product Manager UV & FL, Life Sciences Division, with Hitachi High Technologies America, Dr. Turan Erdogan, Chief Technology Officer with Semrock, Inc., and Ray Kaminski, VP, Fluorescence Group, with HORIBA Jobin Yvon.

What are some recent significant developments in fluorescence?

(Moreno) Instrumentation is improving in several areas: sensitivity, speed, sample measurement automation.

(Erdogan) Some examples include small-animal imaging, live-cell imaging, and applications of imaging to high-throughput screening. A general trend is toward more imaging at higher speeds (even video data rates), taking advantage of increased computing power and data storage capacity. From the optics side, these demands pose challenges to achieve higher throughput and better signal-to-noise ratio optical systems from cleaner light sources, better camera technology, and better optical filtering.

(Kaminski) Most of the new aspects of fluorescence involve imaging and microscopy, in one form or another, especially in fluorescence lifetime imaging microscopy (FLIM). The virtues of lifetime imaging involve such factors as being relatively independent of concentrations of particular species being examined, for example.Another area that appears regularly in discussions is fluorescence correlation spectroscopy and single molecule investigations.

In what applications do you see potential for growth in the use of fluorescence?

(Moreno) The main demand seemingly will come from biosample analysis, however demand for material analysis and environmental analysis will also be strong.

(Erdogan) Today, fluorescence is still most widely used in the life sciences research and development area, but in the future there will be an increasing number of applications of fluorescence in clinical diagnostics. It’s already used in some microplate readers, but in future even fluorescence imaging will be used in diagnostics. Clinical genetics and molecular diagnostics using fluoresence in situ hybridization (FISH) and flow cytometry will become more prominent and routine and has tremendous potential. Commercially available, FDA-approved FISH assays are available (for example, FISH for Her-2/neu genes and oncological Herceptin(R) candidate breast cancer screening). Specialized instrumentation to do FISH more efficiently is already being developed and involves streamlining the observational platform using automated stages and potentially also using several microscope optical trains to simultaneously observe multiple genes and translocations. To get there, instrumentation technology will have to mature to the point of being simpler, cheaper, and more reliable.

(Kaminski) One of the most recent applications is in the field of materials science and has emission wavelengths in the IR. This application is the assessing of the concentration, size, and structure of carbon nanotubes.

How do you think fluorescence spectroscopy (FS) and microplate reader technologies will interact in the near future?

(Moreno) There is no doubt about it. Microplate readers are one of the most efficient ways to do fluorescence analysis.

(Erdogan) There are already some excellent, very flexible grating-spectrometer-based microplate reader technologies, and these will continue to be important for flexible research applications. However, optical fluorescence filters are likely to grow in importance as more instrumentation performs imaging and moves toward simpler, lower-cost, and more reliable platforms.

(Kaminski) Microplate readers are moving further and further toward dedicated units that provide more sensitivity than add-on accessories, though, obviously, less flexibility. In areas such as drug discovery, dedicated units, even those coupled to robotics, provide very rapid characterization of many samples. There is, in these units, less emphasis on spectra than on the intensity changes of probes.

What effect do you think portable XRF analyzers will have on the field?

(Moreno) I believe they are complementary techniques. Use of XRF analyzers may replace fluorescence spectrometers for some applications, but will help promote the need for fluorescence spectrometers when higher resolution and sensitivity are required.

(Kaminski) Most of our experience with XRF is in the fields of materials science, and not in biological areas. We don’t see much real competition for classical fluorescence spectral analysis.

What do you think we’ll see in the field of fluorescence 10 years from now?

(Moreno) This is an increasing market. I believe we will see new applications developed and more familiarization with this analytical technique.

(Erdogan) The possibility of direct fluorescence measurements performed on human patients for clinical diagnostic applications; the $1000 human genome is another possibility.

(Kaminski) Right now, imaging, especially microscopy, at video frame rates, is probably the strongest contender for attention. The imaging markets promise growth in the billion dollar range and areas such as medical diagnostics are especially attractive.

What do you think?

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