Re: resolution target
Posted by
Rosemary.White on
URL: http://confocal-microscopy-list.275.s1.nabble.com/resolution-target-tp3298871p3332343.html
Re: resolution target
Another cheap source of (bits of) diatoms is dust from kitty litter, which is usually mostly diatomaceous earth.
cheers,
Rosemary
On 24/07/09 10:54 PM, "Keith Morris" <kjmorris@...> wrote:
If it’s decent samples to view under the microscope then I also use Klaus Kemps diatom slides, and they are well suited to phase contrast microscopes and just bright-field [where they can look a tad dull]. Always buy the 50 [mine are 100] diatom exhibition set though, it’s well worth the extra £s over the simple line of diatoms [the exhibition diatoms are arranged in a large circle, see links below]. These slides are cheaper to buy direct from Klaus than via eBay. I avoid the ‘penny farthing’ cutesy sets.
I do produce my own Foraminifera test slides that can be fun. You can get these ‘sand’ samples from ebay. Search ‘Sand Sample (Foraminifera) make Microscope microslides’ in ebay.co.uk. See: http://www.fernwood-nursery.co.uk/sand/danny.htm for things to do with them [these shells appear larger than those found in the eBay Foraminifera sand samples]. Buy them for a few quid at: http://cgi.ebay.co.uk/Sand-Sample-Foraminifera-make-Microscope-microslides. You can just scatter the ‘sand’ lightly over a slide and seal on a cover slip with nail varnish. You find micro snail shells [about 200um wide], bits of larger shells, arthropod fragments, coral fragments and such like, as well as quartz sand that looks good under phase contrast [and best of all under darkfield with two polarizer’s, e.g. from DIC optics]. Again a tiny bit dull in comparison just under bright-field, but still well worth a view, although they are very 3D so expect more depth of focus effects compared to flatter diatoms.
In addition I have a couple of standard high quality stained histological sections of plant stems [supplied by Leica] that look very nice under both brightfield and fluorescence [microscope engineers seem to use these a lot]. I also use a few tatty H&E stained animal tissue to check evenness of fluorescence as they fluoresce well [along with dried salt crystals doped with 0.02 um FITC spheres look nice and do the same job]. I also have both the Invitrogen slides [triple fluorescence labels of BPAE cells and a kidney section] I mentioned in my last post – great for confocals but no good for brightfield. Even dried felt pen marker dots of various colours can look OK on plastic Petri dishes - I use them to easily test which way the inverted microscope is focusing [say for automatic Z stacks] or whether the XY view is inverted on the VDU screen. Plus there’s things like cheapo laser printer toner soot [ultrafine very black spheres], gel polymer spheres or fantastically expensive fluorescent particles of known size like Invitrogen’s FocalCheck. For testing optics, i.e. cleanness of the lenses or evenness of illumination, really any decent suitable specimen will do.
For kids and/or fun do try and grow your own crystals on a glass slide. Make a saturated salt solution [e.g. NaCL or CuSO4]. Place a large drop on a slide and leave to evaporate. As the water evaporates the crystals form in the solution – best viewed well before the water evaporates completely. NaCl crystal cubes look great as say 40 to 200x mag, and are fine under bright-field [but be careful not to spill the solution is using an inverted microscope].
I also have a set of J B Dancer microphotographs that can be amusing [well for a microscopist] – my slides are 1990’s copies of Dancers originals and cost £30 for 5 different images from eBay: Queen Victoria and babies, Raphael’s Madonna and child [so like Victorian naturalists you can see God down the microscope], etc.. They are easily forged so copies are fine. See http://www.gpmatthews.nildram.co.uk/microscopes/microphotos.html
I use all of the above for microscope fun at schools outreach program and any schoolkids visiting our labs on ‘work experience’, and these are linked into our cytogenetics metaphase chromosome and interphase nuclei ‘real science’ preps.
I’ve put a few of the images of the things I’m discussing above on our website: http://www.well.ox.ac.uk/cytogenetics/images.htm.
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From our website a few more links that may be useful:
Optical Microscope Enthusiast Sites
Microscopy UK - thousands of microscopy related pages for kids & enthusiasts
http://www.microscopy-uk.org.uk <http://www.microscopy-uk.org.uk>
Ask-a-microscopist and list-server postings [with an electron microscopy bias]
http://www.microscopy.com <http://www.microscopy.com>
101Science.com's microscope pages for older school-kids & parents
http://www.101science.com/Microscope.htm <http://www.101science.com/Microscope.htm>
The Science for Fun website for older school-kids & parents
http://www.funsci.com/texts/index_en.htm <http://www.funsci.com/texts/index_en.htm>
The McCrone atlas of microscopic particles - many images are pay to view
http://www.mccroneatlas.com <http://www.mccroneatlas.com>
Klaus Kemp's diatom & butterfly scale microscopy slides - to purchase
http://www.diatoms.co.uk <http://www.diatoms.co.uk>
The Royal Microscopical Society
http://www.rms.org.uk <http://www.rms.org.uk>
Olympus Bioscapes site - Beautiful images from the microscope
http://www.olympusbioscapes.com <http://www.olympusbioscapes.com/index.html>
Regards
Keith
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Dr Keith J. Morris,
Molecular Cytogenetics and Microscopy Core,
Laboratory 00/069 and 00/070,
The Wellcome Trust Centre for Human Genetics,
Roosevelt Drive,
Oxford OX3 7BN,
United Kingdom.
Telephone: +44 (0)1865 287568
Email: kjmorris@... <[hidden email]>
Web-pages: http://www.well.ox.ac.uk/cytogenetics/ <http://www.well.ox.ac.uk/cytogenetics/>
From: Confocal Microscopy List [[hidden email]] On Behalf Of Rosemary White
Sent: 21 July 2009 23:22
To: CONFOCALMICROSCOPY@...
Subject: Re: resolution target
Another way to test optics is to coat a clean, but not ultraclean, glass slide with a reasonable amount of gold (i.e. thicker than you’d normally use for SEM) in a standard sputter coater, then wipe the coated surface very gently. This will produce tiny pinholes, just select the size you want to use. To preserve the surface, glue a long coverslip on top with your preferred mountant, that way you have the correct amount of glass between objective and object. It’s a good way of testing chromatic aberration, for example.
cheers,
Rosemary
Rosemary White
CSIRO Plant Industry
GPO Box 1600
Canberra, ACT 2601
Australia
ph 61 2 6246 5475
fx 61 2 6246 5334
On 22/07/09 1:49 AM, "Julio Vazquez" <jvazquez@...> wrote:
Hi Thomas,
Mr Klaus Kemp in the UK used to make diatom slides, including one with 8 species of diatoms covering a broad range of resolutions. The slides were about 20 Euros or so. I am not sure whether he is still in business though. Below is his web site, and the list of diatoms on his 8-form test plate.
Julio.
http://www.diatoms.co.uk/
- Amphipleura pellucida 270 nm
- Frustulia rhomboides 300 nm
- Pleurosigma angulatum 525 nm
- Surirella gemma 500 nm
- Nitzschia sigma 440 nm
- Stauroneis phoenicentron 720 nm
- Navicula lyra 1250 nm
- Gyrosigma balticum 670 nm
There also used to be an article by Dave Walker: Counting the dots: Giving Microscopes a workout using diatom test slides at
www.microscopy-uk.org.uk/mag/artoct99/dwdiatom.html <http://www.microscopy-uk.org.uk/mag/artoct99/dwdiatom.html>
the article has been inaccessible for a while though
--
Julio Vazquez
Fred Hutchinson Cancer Research Center
Seattle, WA 98109-1024
http://www.fhcrc.org
==
On Jul 21, 2009, at 5:11 AM, Thomas Aabo wrote:
Hi
Does anyone know a good (cheap) place to get a positive high resolution target for a bright field microscope (50X, N.A. 0.55). Inside the EU would be best.
Thanks
Thomas
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Thomas Aabo
Phone: +45 35333636
M.Sc., Ph.D student, taa@...
University of Copenhagen
Department of Food Science
Rolighedsvej 30
1958 Frederiksberg C
Denmark
www.ifv.life.ku.dk <http://www.ifv.life.ku.dk>
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