White LED Ring Light

The White LED Ring Light from Aven, Inc. combines seven brightness choices with four lighting modes for customized adaptation to any specimen or objective. Sixty long-lasting LEDs provide soft, no-shadow illumination for life science labs, industrial inspection and materials analysis. The flicker-free white lights retain color integrity over time and operate at low temperature to minimize user discomfort, even for long spans.

"Full" mode operation uses all of the evenly distributed LEDs (35,000 lux), or users can illuminate one, two or three quadrants. Seven brightness settings add further precision. Applications include biotechnology research, health care lab work, forensics, gemology and failure or defect analysis of small parts. Installing the ring light below a microscope lens allows a working distance of 50 to 160 mm. The plug-in accessory has a 40 mm inner diameter and 70 mm outer diameter.

For more information visit www.aveninc.com.

IR now available from LED microscope illuminator

DiCon LED has expanded the wavelengths available from its LED Microscope Illuminator to include 730 nm and 850 nm options. These IR wavelengths are useful for applications like non-invasive real-time imaging, IR fluorescence, as well as standard microscopy and machine vision.

The Microscope Illuminator is a replacement for halogen and tungsten light sources. LED illumination offers low energy expenditure, low power consumption, and instant wavelength switching. The user can manually adjust pre-programmed color settings and intensity levels or create customized strobe effects. Additionally, through DiCon's LightControl software, the user can program custom light sequences, or “Profiles” that control color, fade, modulation frequency, and duration. These “Profiles” are then accessible manually after being downloaded into the unit, or they can be externally triggered for syncing with cameras and other peripheral equipment.

DiCon LED distributes the LED Microscope Illuminator through Edmund Optics. More information here.

High power red and green LEDs for fluorescence microscopy

Prizmatix has added 520-nm and 630-nm ultra high power LEDs to its modular OptiBlocks family. The LEDs can be used as excitation sources for fluorescence microscopy. The UHP-Mic-LED-520 provides greater than 0.5 Watts of collimated green LED output power and its LED driver supports CW or pulsed operation. The UHP-Mic-LED-630 provides greater than 1 W of collimated red LED ouput power. Both are compatible with Prizmatix modular microscope LED light source products, and allow narrowing of the LED spectrum with an optional band pass filter installed in the head. The light sources can also be used for small animal imaging, photoactivation, FRAP, and FISH.

More information at www.prizmatix.com.

LED flashlight used as fluorescence microscopy light source

Mercury gas discharge lamps, the traditional light sources for

fluorescence microscopy, come with several disadvantages. They have a limited lifetime, a fluctuating intensity, give off heat, and can sometimes explode. LED illumination overcomes these limitations, but most commercial LED illumination systems are expensive because they are made to excite at many different wavelength ranges.

Researchers from Vanderbilt University wanted to find a cheaper way, so they tried an off-the-shelf LED flashlight as an illumination source for fluorescence microscopy. They picked out the brightest flashlight available at a camping store, which was a $50 Inova Bolt 4.6 W/6 V flashlight. It had a strong emission in the 440 to 480 nm range, which is useful for excitation of several common fluorescence probes including enhanced GFP. They hooked up the flashlight to a power supply so that it could be turned off and on from outside the light-tight box they were using and also created an adaptor to fit the flashlight to the microscope’s fluorescence lamp port.

Although the flashlight was less intense than a mercury light source, they did achieve images with the LEDs that were comparable to those from a mercury light source by increasing the CCD camera exposure to four to five times that used for a 100 W mercury lamp. The researchers say that the power supply and flashlight together costs around $90, less than a single replacement mercury lamp.

Read more about this work in the paper:

J.B. Robertson, Y. Zhang & C.H. Johnson. Light-emitting diode flashlights as effective and inexpensive light sources for fluorescence microscopy, Journal ofMicroscopy, Vol. 236, Pt 1 2009, pp. 1–4, doi: 10.1111/j.1365-2818.2009.03208.x

Five Digital Microscopes Under $300

As LEDs and USB connections have come down in price some quite inexpensive digital microscopes have come on the market. In addition to entertaining the kids (and adults too) and providing a closer look at collectables like coins or stamps, these microscopes can also be used for inspection, documentation, dermatology, and biology.

1. The Dino-Lite Digital USB microscope. $249.00 USD

I've used this microscope for education purposes, and it works great. Easy for kids to use, and just as much fun for adults. Just hook it up to a computer and take a look at pond water, hair, clothing, insects, flowers, and more. It takes great images at up to 200X magnifaction. More information here.  

2. LCD Celestron Digital Microscope. $299.00 USD

Looks like a normal microscope, but wait there's an LCD screen instead of the normal eye piece. No need to hook up a computer to look at digital images of slides, but you can transfer your images to a computer via USB. The microscope has up to 400X optical magnification, but bump that up to 4000X when you add in the optical zoom. More information here. 

3. Mighty scope Digital Microscope  $199.00 USD

This handheld USB microscope is almost identical to the Dino-Lite microscope. It has up to 200X magnification. More information here. 

4. USB Digital Microscope Camera System. $99.00 USD

At 130X, a little less magnification than other models, but also costs less than $100. More information here.

5. Turn your web cam into a digital microscope. 

It you like to tinker, try this out. Check out instructions here. 

Five resources on LED microscopy illumination

1. Tutorial on Zeiss product: LED illumination system for widefield fluorescence microscopy

2. Leica product: LED fluorescence light source. 

3. Thorlabs LED products:

Collimated LED Light Source

Modulated LED sources for FLIM

4. Article covering CoolLED product (available from Olympus): "LEDs for fluorescence microscopy" 

5. Research paper: "A new type of microscope illumination and its use in microbiology".

LED Modules for stereomicroscope illumination

The right illumination can make the inspection and study of various materials easier and more precise. LED illumination is growing in use because LEDs offer benefits such as a long lifetime and lower energy use.

A new set of LED illumination modules are being shown by Leica Microsystems at the Systems Integration in Microelectronics (SMT) fair in Nurenberg, Germany this week. The modules are designed to illuminate difficult material samples viewed with a stereomicroscope, have reproducible illumination settings, and maintain constant color temperature during dimming.

The modules include:
• LED3000 NVI: The nearly vertical illumination (NVI) light path of this illumination module can illuminate samples with indentations and drill holes, which are challenging to view with standard illumination.

• LED5000 CXI: This module’s coaxial illumination (CXI) is useful for enhancing contrast of flat, highly reflecting surfaces such as wafers or polished metal samples.

• LED5000 RL: The ring light (RL) can be used for a variety of applications. The module’s switchable segments allow extra information to be obtained without moving the sample.

• LED5000 MCI: The multi-contrast illumination (MCI) module creates particularly high contrast on the sample. The flat angle of its oblique incident light lets can reveal the fine irregularities and defects such as scratches and dust particles.

More information here.