Experimental facilities & confocal microscope information

Located in Emerson Hall 347, 350, & 360 -- see photos of our lab

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Capabilities we have

We can do lots of cool things. Our facility is always upgrading (shopping), and our capabilities currently include:

TWO confocal microscopes:

VisiTech "Vt-eye" confocal
Attached to a Leica inverted microscope
30 images per second (512 x 512 pixels); up to 400 images/s for reduced field of view
Ultra-fast 3D acquisition: 256 x 256 x 100 pixel 3D image, 1 per second

Noran "Oz" confocal
Attached to a Leica inverted microscope
30 images per second (512 x 480 pixels); up to 240 images per second (reduced field of view)
Currently not working -- prognosis unknown (July '09)
If you are interested in using either instrument, contact Eric Weeks at <weeks(at)physics.emory.edu>
Click here to learn how a confocal microscope works.

Regular, brightfield microscopy:
Magnifications from 1.6x to 160x. (The best resolution we can get is 0.2 microns.) See table below for more information on our lenses. We have both inverted and upright microscopes. We also have a rotation stage: we can rotate the sample in a horizontal plane while we're looking at it.
Differential interference contrast (DIC) microscopy:
This technique is useful for looking at thin samples, or samples with low contrast.
Fluorescence microscopy:
Biologists love this, as they have all sorts of clever ways to make odd things fluoresce. Physicists (like us) like using boring old fluorescent particles. (See our links page for sources of these particles.)
Temperature control:
We have a temperature control system for the microscope, which works from room temperature up to about 40 degrees C. We also have a water bath which can be used to control temperatures.
Pipette puller:
We have a pipette puller and a microforge, suitable for making glass pipettes with tip sizes down to a few microns.
Digitizing video tapes:
More than just microscopy, we also have a nice system for digitizing video tapes. We can also digitize video signals straight from the camera.
Online frame-grabbing:
We can store video images directly onto hard disk at video rate without losing any images. The files are big (one minute of data fills a CD - 650 MB!) but we have CD and DVD burners too.
Analysis:
We use IDL to analyze our images. We have several Linux computers to do this with, and access to the physics department's Beowulf cluster. The confocal also comes with some adequate (but not great) software for 3D visualization, which helped make the pictures shown below.
Particle tracking:
Our favorite analysis technique is tracking the motion of individual colloidal particles. Best of all, we can do this for several thousand particles simultaneously, in three dimensions.

Particle synthesis:
We have started making fluorescent colloidal PMMA.

Miscellaneous Gadgets:
These include a refractometer, several viscometers, and several simple cameras. We also have a nice Hamamatsu video enhancement box.

Microscope objectives that we have

Magnification/NA	best slit (Noran)	image size (Noran)	um/pixel (confocal)	theoretical resolution	working distance	comments
1.6x / 0.05 air	-	-	-	6 um	3.4 mm	A
5x / 0.15 air	-	-	-	3.3 um	12 mm	A
10x / 0.22 air	10 um	600 x 560	1.3 um	1.3 um	5.8 mm	-
10x / 0.40 air	10 um	600 x 560	1.3 um	0.7 um	2.2 mm	-
10x / 0.40 oil	10 um	600 x 560	1.3 um	0.7 um	0.36 mm	-
20x / 0.40 air	?	300 x 280	0.65 um	0.7 um	1.9 - 3.2 mm	B
20x / 0.70 multi (oil)	10 um	300 x 280	0.65 um	0.4 um	250 um	C
40x / 0.55 air	?? um	150 x 140	0.327 um	0.5 um	1.9 - 3.3 mm	B
40x / 1.25 oil	10 um	150 x 140	0.327 um	0.23 um	100 um	-
63x / 0.70 air	25 um	95 x 89	0.207 um	0.4 um	1.8 mm	D
63x / 1.20 water	15 um	95 x 89	0.207 um	0.24 um	220 um	E
100x / 1.35 oil	25 um	60 x 56	0.117 um	0.21 um	90 um	-
100x / 1.40 oil	25 um	60 x 56	0.117 um	0.20 um	90 um	F

NOTES:

NA is Numerical Aperture. Theoretical resolution is (wavelength/(2 NA)); the wavelength assumed above is 568 nm.
Image size is in (microns x microns).
Image size and microns/pixel are for a zoom of 1.0; you can change this with the software (although it doesn't affect the actual resolution)
Some objectives have been purchased more recently than others, I need to update the ?'s in some of the entries for the newer lenses.
comment A: our low-magnification lenses aren't intended for confocal use.
comment B: These two are long working distance lenses, and both have correction collars for glass thicknesses from 0.0 to 2.0 mm.
comment C: this lens can work with a variety of immersion fluids, including water, glycerol, and oil. In general, consider this an oil immersion lens.
comment D: this is a long working distance lens. It has a coverslip correction collar, and can work with coverslips from 0.1 mm thick up to 1.3 mm (in other words, a microscope slide or petri dish).
comment E: best for aqueous samples, such as most biological samples. This is a really nice lens.
comment F: the "highest power" lens. It helps if your samples have an index of refraction similar to oil, in other words, close to n=1.5.

Some 3D confocal pictures:

Pictures by Piotr Habdas, showing colloidal particles which have formed a gel. Another image of the same sample is the background for this web page.

Other confocal microscope facilities that Eric Weeks used to help maintain:

You may notice similarities between those web pages and this one... I was the webmaster for those confocal facilities, too.