Posted by
Barbara Foster on
URL: http://confocal-microscopy-list.275.s1.nabble.com/FW-Deconvolve-1-42-Components-Setup-now-OK-tp590745p590748.html
Search the CONFOCAL archive at
http://listserv.acsu.buffalo.edu/cgi-bin/wa?S1=confocal
Dear Glen
As a strategic consultant in microscopy, I get to see the latest
technology and there is, indeed, a great deal of flurry about LED
technology. In the summer of 2006, I had a chance to evaluate the
AFTER/FluoLED from Fraen and was very impressed with the design, ease of
use, and flexibility. I have been working on assignment with Fraen
more recently and was surprised to see how much both LED technology and
this product line had evolved. So here are observations on both LED
technology in general, and the Fraen system in particular.
Fraen's FluoLEDs are now available in UV (354nm), Royal blue (450nm),
Blue (480nm), Cyan (505 nm), Green (535nm) Yellow (590nm) and red
(630nm). While Fraen is a new name in the microscopy arena, most of
you already know them: they are the world's largest manufacturer of
the LEDs used for the pointers/indicators for the speedometers, gas
gauges, etc., on the dashboard of your cars.
Until recently Fraen's AFTER/FluoLEDs were only available in transmitted
light version for upright microscopes, currently, over 17 different
models from all the major manufacturers and several of the smaller
ones. For us "old timers", transmitted light has
typically been seen as less efficient, but the superb images from FluoLED
tell a very different story: Bright features against wonderfully
velvet black background. In other words: great S/N. Fraen
will be releasing the first systems for inverted stands next month and
have begun work on an epi version as well.
As with any technology, there is up side/down side to LEDs
The good news is the consistency, lack of fuss, and economy of
LEDs. When they are on, they are on. When they are off and
you need them on, you can turn them on immediately - no cycle
time.
Also, they exhibit much less drop off over time than HBOs. That
time factor is critical. Life expectancy of an HBO is on the order
of 200-300 hrs; for Fraen's LED's (I don't have figures on the others)
30,000 hrs. No error in decimal points here: you can run them 8 hrs
a day, 5 days a week, for 5 years without changing a lamp. If you
plot drop-off versus time, a 100 fold increase in time is significant,
especially for those of us doing long term experiments.
When it comes time to switch out the lamp, there is no alignment, no
disposal issue.
The economy issue is also an interesting. Fraen's European office
did the following calculations (Euros) for the LED cassette for a
standard Blue excitation kit vs. an HBO arc lamp:
Cost of LED cassette:
Eu720
Cost of HBO lamp: 160
Lifetime LED casette: 30,000hrs
Lifetime HBO lamp:
300 hrs
Eu/hr LED cassette: EU
0.024
Eu/hr HBO
lamp: Eu 0.53
Assumption: if you run both systems for 2000 hrs/year
Cost of LED cassette/yr:
Eu48
Cost of
HBOs/year: Eu1060.
Savings, using LEDs: Eu1012
One more bit of good news: LEDs are also a much cooler source so there is
dramatically less photobleaching.
The down side really isn't very down, just something to be aware
of.
Because of the state of LED technology, green and yellow LEDs generate
less power so the resulting images will be somewhat less bright than with
HBO. This is not much of an issue when the fluorescence is viewed
at magnifications up to about 60x but if you routinely use 100x
objectives, you should run the test to see if it is a problem with your
particular samples. The good news is (a) for green LEDs, research
is powering ahead. Fraen expects to have new, brighter LEDs in Feb
08. (b) For Yellow (Texas red, etc.), research is slower.
However, they also have a good news side: they exhibit better S/N ratio,
even at the lower power, than HBO.
The FluoLED family has a number of things to recommend it:
a. They have engineered a clever "multi-cube" device so that
you can have 1 LED, 2 LEDs, or 3 LEDs and can switch conveniently from
one to another
b. For multi-user labs, the LED cassettes can be switched quickly and
easily. This feature reminded me of the old Reichert Polyvars, one
of my favorite microscopes, especially for teaching. The
fluorescence (and reflected light DIC and Darkfield) cubes came on
"lolly pop" sticks so that you could just slide in what you
needed. FluoLED has mimicked that flexibility with their cassette
approach. A lab can have a set of cassettes sitting in a drawer
next to the microscope or each group can have what they need in their own
area, so they can have whatever excitation/emission they need by just
plugging in their cassette and tightening the locking screw.
Immediate change out... no alignment!
c. Fraen has engineered intelligent electronics into their
controllers. Different wavelength LEDs require different amperages
to drive them. With Fraen's system, when a cassette is plugged into
position, the controller intelligently senses which LED is in the
cassette and provides the appropriate amperage, even with the 3 cassette
system.
d. The controller also allows the user to change intensity so that you
can balance different channels for optimum imaging.
e. Finally, and as a past high school teacher, I loved this one... Fraen
has engineered less expensive "baby" systems in Blue and Royal
blue, so that we can finally get fluorescence into teaching labs.
That's the story. I hope it was helpful. I am at Neuroscience
this week and LEDs are, indeed,grabbing a lot of interest.
Best regards,
Barbara Foster, President
We've moved!
Microscopy/Microscopy Education
7101 Royal Glen Trail, Suite A
McKinney TX 75070
P: (972)924-5310
Skype: fostermme
W:
www.MicroscopyEducation.com
MME is now scheduling customized, on-site courses through
December. Call us today for details.
P. S.
Need a good general reference or light microscopy text for next semester?
Call us today to learn more about "Optimizing LIght
Microscopy". Copies still available through MME... even for
class-room lots ... and we give quantity discounts. Just call us here in
the MME office for details.
At 07:21 AM 11/6/2007, Gerard Whoriskey wrote:
Search the CONFOCAL archive
at
http://listserv.acsu.buffalo.edu/cgi-bin/wa?S1=confocal
Hi Glen,
The argument for LED systems is very strong on reliability and
operational
costs and is continually improving with regard to performance, measured
in
choice of wavelengths and intensity.
I assume that in your confocal set-up you are only using the mercury
based
bulb system to check and align samples and that you only need excitation
regions that match the laser lines you are using. An LED system that you
can switch on and off as you please is ideal for such applications and a
very cost effective replacement to bulbs.
Commercial bit:
We have only recently included 445nm and 505nm options to our range. Now
users can choose from 7 options of 400nm, 445nm, 465nm, 505nm, 525nm,
595nm, and 635nm.
I will contact you directly with more commercial information.
Best Regards,
Gerry
Gerard Whoriskey
Development Engineer
CoolLED Ltd
CIL House
Charlton Road
Andover
Hampshire
SP10 3JL
Mob: 07789535762
Tel: +44 (0) 1264 321321
Dir: +44 (0)1264 320984
web site:
www.coolled.com