MicrobeHunter.com Microscopy Forum

Acridine orange is a fluorescent dye that can be excited with blue-cyan light and upon binding do DNA and RNA it fluoresces in green and red respectively (there are of course other things that make it glow green or red). Here I added the tiniest drop (< 100 nanoliters) of an acridine orange stock solution to a drop of pond water and captured a few images I decided to share. All images were acquired with the following fluorescent setup: 450-490 bandpass excitation filter, 510 dichroic mirror and 515 longpass filter.


A paramecium I think. Plan 16/0.32


Merismopedia. Neofluar 40/0.75


Colonial algae. Neofluar 40/0.75

wonderful images ... well done.

I see the upgrade you mentioned is paying dividends!

viewtopic.php?f=24&p=73559#p73559

Thanks 75RR. Its very refreshing to learn new techniques.

Very cool images.

And seems even micro-holiday spirited: deck the slides with drops of acridine, fa la la la la la . . .?

Thanks Pete. The green and red touch certainly adds to the Christmas spirit.

Thanks for these beautiful results, Wes. Was that first image a ciliate, and was that protozoan still active ( as in a gentle vital strain treatment with Janus Green)?

It would be good to know how long you exposed these pond organisms to your dilute stain ( approx. that is), before these stain effects manifested. Thanks for sharing this bench work, Wes.

Charlie guevara

charlie g wrote: ↑

Fri Dec 27, 2019 8:54 pm

Thanks Charlie

The majority of ciliates I spotted were moving around actively. The samples were exposed to AO from anywhere between 10 to 40 minutes. I think the intense illumination is what kills or at least impairs them after a period of observation. A rather dramatic end meets amoeba species stained with AO. They possess intensely fluorescing lysosomes (stained orange due to the low pH) and after about a minute or less of observation the lysosomes suddenly dissolve and the cell disintegrates in the matter of seconds. Below is an example before it disappeared.

BEAUTIFUL IMAGES!...

THE BEST,
BILLT

Awesome shots Wes!
tgss

Thank you billt and tgss!