Fluorescence microscope game: count the glow
A box of five slides, a focus wheel and a light that goes from white to blue. Find ten cells glowing with green fluorescent protein.
Glow gene only
I added a plasmid encoding green fluorescent protein, or GFP. Green cells have taken up and expressed the DNA. I use this positive control to check delivery.
What this simulates
What you do
You pick a slide from a box of five and drag it around under the eyepiece. You turn the focus wheel until the cells look crisp, and slide the light from white to blue. Then you click a glowing green cell to count it, and you need ten in total. The game won't count while the image is blurry or the light is still white. Clicking somewhere that isn't glowing is a miss, and each miss costs five points.
Two of the five slides have no GFP marker, so nothing glows on them. That is the point of those slides, and they are there to show what background looks like.
The real technique
Green fluorescent protein, or GFP, glows green when blue light hits it. Cells that have taken up a plasmid carrying GFP and are making the protein show up against a dark background. In white light you see the cells themselves. In blue light you see only the ones that glow.
The images are real: I took them of HCT116 cells, a human cell line used in research, after adding different plasmids. The slides are a control with no plasmid, a GFP-only positive control, Cas9 with GFP, Cas9 plus a second plasmid carrying a tag patch, and a prime editor with no GFP marker. I adjusted the brightness and added the green tint for display. Focus and counting are game effects.
What you learn
Why a no-plasmid control and a positive control come first, and how green cells show that DNA was delivered and expressed. You also see why that isn't the same as showing that an edit worked: for that, the cells' DNA has to be read.