Mood music. You might want to wait till after gorgeous John Butler finishes giving the introduction to the song and then start reading . Or, well, do as you please:


Once upon a time, on a different Era, I documented the point of view of lab mice.
And while doing that task I got a genetically modified fluorescent mouse and took it home.
I decided that the rescue of the fluorescent mouse (it was a "waste" mouse, too expensive to feed if not included on an experiment) was perfectly within the spirit of Humanitarian Crisis (yeah, son, we had to join a group back then..), because, isn't a mouse genetically modified to be fluorescent a symbol of now being the best of times and the worst of times, that bittersweet "we can do anything: let´s do everything" feeling? (thanks, Hey Man Jackson).

So now, I had the opportunity to task by documenting this animal, which I believe qualifies as an animal that you rarely see. (Well, that you rarely see, because I see it every day, clean his cage, etc.)
But there is a problem: at plain sight, it looks exactly as a regular mouse.
So I can document it allright, say, running on his wheel, swimming, sleeping on my hoodie pocket, a day in the life of a very rare mouse, but is going to look exactly as a day in the life of any other mouse.
And since the instructions of the task state that "other than that you´re on your honour", I could very well be tasking on a technicality. Which would be completely wrong.

So I absolutely needed to document that my mouse glows in the dark when exposed to UV light.
But that turned out not to be easy.
First I tried shining the light of a Spy-Pen on it (failure!).
Later we took it to the school musical, that had black lights and all. Nothing.
Then I actually bought a black light bulb and installed it on a table lamp. Another failure.
Not enough UV light? Not the appropriate wavelenght?
Suspicion setting in. Did I really have a fluorescent mouse?
Maybe my friend at the animal facility had given me just any other mouse. Or someone there was a mice switcher. Or glow-in-the-dark-mice were just an urban legend. Aargh.

So, three days ago the mouse had to come with me on a field trip to the MIS, the molecular imaging system that we have at the lab, (that´s my Orwellian place of work, located within a dreaded corporate building).
The MIS is a cool piece of equipment generally used to produce the most boring images you can imagine: series of stripes at a various distances on a rectangle, but, yes, in super-high resolution.

I put the mouse inside the MIS, closed the door, turn on the transilluminator UV light, turn the image sensor to capture a dozen 1 sec exposure images every 5 seconds. Voilá!
Well, not really voilá, because the mouse didn´t sit still to get his picture taken.
Many frames of empty space.
Damn.
Is the mouse not fluorescing or is it mouse just hiding?
Tried again using the overhead white light. Just to see if he was there at all.
Time lapse capture: more empty pictures.
Hiding, then.
Phew.
Some of the pictures showed parts of the mouse happily walking around.
As you can see, it looks as a perfectly regular mouse.





Mmm. The critter needed to be restrained.

(I forgot to take pictures of this part with the actual fluorescent mouse, so I am using a dummy here, in case you´re wondering.)

I located a handy plastic bag holder, of the very expensive kind used in research labs as miniwaste baskets.



I put the mouse inside.






Then I put the plastic bag holder holding the mouse in place inside the MIS and closed the door.





This is how the time-lapse series looked:




Yay! I do indeed have a glow-in-the dark mouse at home!

It glows. For real.



So, this is my dear GFP mouse, as seen from above while standing on a UV transilluminator.
All his live cells glow green under UV light, because they carry the green fluorescent protein from the sea pansy, Renilla reniformis, a soft coral.
Here you see that its skin glows green (well, you see it glow white because the CCD sensor of the MIS is monochromatic), and that the glow is more intense in the regions with no fur: feet, ears. Fur doesn´t glow because hair is made of dead cells. And newborn GF mice are all glowing green.

This last image is digitally modified for color. It shows how the mouse would look if the MIS had a RGB image sensor, instead of being just boringly monochromatic. Or how the mouse would have looked to people small enough to get themselves inside the MIS with it. Eerie green glow. Lighting up the plastic bag. Which you rarely see.