Posted by
George McNamara on
URL: http://confocal-microscopy-list.275.s1.nabble.com/Boosting-bright-field-resolution-with-dichroic-filters-tp7583983p7583992.html
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Diatoms in bulk ... maybe in your (or a colleague's) kitty litter.
Diatomaceous earth
https://en.wikipedia.org/wiki/Diatomaceous_earthDiatomaceous earth consists of fossilized remains of diatoms
<
https://en.wikipedia.org/wiki/Diatom>, a type of hard-shelled algae
<
https://en.wikipedia.org/wiki/Algae>. It is used as a filtration
<
https://en.wikipedia.org/wiki/Filtration> aid, mild abrasive in
products including metal polishes and toothpaste
<
https://en.wikipedia.org/wiki/Toothpaste>, mechanical insecticide
<
https://en.wikipedia.org/wiki/Insecticide>, absorbent
<
https://en.wikipedia.org/wiki/Absorption_%28chemistry%29> for liquids,
matting agent for coatings, reinforcing filler in plastics and rubber,
anti-block in plastic films, porous support for chemical catalysts, cat
litter <
https://en.wikipedia.org/wiki/Cat_litter>, activator in blood
clotting <
https://en.wikipedia.org/wiki/Blood_clotting> studies, a
stabilizing component of dynamite
<
https://en.wikipedia.org/wiki/Dynamite>, and a thermal insulator
<
https://en.wikipedia.org/wiki/Thermal_insulation>.
(I first learned of it from using kilograms in the filtration system of
our backyard pool).
Or
http://www.amazon.com/Diatomaceous-Earth-Food-Grade-10/dp/B00025H2PY Diatomaceous Earth Food Grade 10 Lb
<
http://www.amazon.com/Diatomaceous-Earth-Food-Grade-10/dp/B00025H2PY/ref=sr_1_1?ie=UTF8&qid=1436789646&sr=8-1&keywords=Diatomaceous+earth>
by DiatomaceousEarth
Diatomaceous earth (de) is made of tiny, fossilized diatoms (aquatic
organisms) that accumulated over millennia in fresh water lakes. When
mined and left untreated, this amazing product can be used in hundreds
of different ways. However, not all diatomaceous earth is created equal.
While most other manufacturer's hand scoop de into zip lock bags,
diatomaceous earth brand de is professionally packaged using stainless
steel equipment. Because of this process, you can be confident there are
no contaminants in your food grade diatomaceous earth.
Maybe you could repackage this from "food grade" to "microscope grade".
Same order could include
http://www.amazon.com/100g-Fluorescein-Powder-Chemical-Reagent/dp/B00FJ64S3U 100g of Fluorescein Powder, Chemical Reagent
<
http://www.amazon.com/100g-Fluorescein-Powder-Chemical-Reagent/dp/B00FJ64S3U/ref=sr_1_1?ie=UTF8&qid=1436789750&sr=8-1&keywords=fluorescein>
by Aldon Corp
$44.95
<
http://www.amazon.com/100g-Fluorescein-Powder-Chemical-Reagent/dp/B00FJ64S3U/ref=sr_1_1?ie=UTF8&qid=1436789750&sr=8-1&keywords=fluorescein>+
$6.74 shipping
Or make transgenic diatoms (
http://www.ncbi.nlm.nih.gov/pubmed/25297896
... centric diatoms sounds good for FFTs, and their abstract mentions
firefly luciferase and Azami-Green GP genes), fuse their silica binding
protein (Si-tag, see, for example,
http://www.ncbi.nlm.nih.gov/pubmed/21277372 ... Ecoli L2 ribosomal
protein and its 203-273 peptide apparently are SiBP's and has been fused
to EGFP,
http://www.ncbi.nlm.nih.gov/pubmed/22926644) to GFP, RFP,
photoswitchable FP, iRFP, etcFP,
and sell that/those on amazon.com
enjoy,
George
On 7/13/2015 4:26 AM, Steffen Dietzel wrote:
> *****
> To join, leave or search the confocal microscopy listserv, go to:
>
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> *****
>
> Dear all,
>
> two questions, first about the formula:
>
> I thought 0.61*lambda/(NA) (Rayleigh) would be the appropriate
> formula for self-luminous objects (dark field, fluorescence) while for
> bright field the fitting variant of the Abbe formula should be
> applied: lambda/NA-obj for central illumination, lambda/2NA for NA-obj
> = NA cond and, in general, lambda/(NA-obj + NA cond), provided that
> NA-obj is equal or bigger than NA-cond.
>
> It seems though, that others are happy with 1.2*lambda/(NA-obj + NA
> cond). Where does the 1.2 (or 2*0.6) in a bright field situation come
> from? Would that be the paper by Hopkins and Barham (1950), that Mike
> was referring to? Because I have no hope of understanding this paper
> by reading through during this life (Lots of formulas my biologist's
> brain is not flexible enough to adjust for).
>
> Second:
> Is there a good source for diatoms that can be stained with
> fluorescent dyes and self-mounted, as George suggested? I have a few
> diatom slides for teaching (Pleurosigma), but they came already mounted.
>
> Steffen
>
>>
>>
>> --
>> ------------------------------------------------------------
>> Steffen Dietzel, PD Dr. rer. nat
>> Ludwig-Maximilians-Universität München
>> Walter-Brendel-Zentrum für experimentelle Medizin (WBex)
>> Head of light microscopy
>>
>> Marchioninistr. 27
>> D-81377 München
>> Germany
>
--
George McNamara, Ph.D.
Single Cells Analyst
L.J.N. Cooper Lab
University of Texas M.D. Anderson Cancer Center
Houston, TX 77054
Tattletales
http://works.bepress.com/gmcnamara/42