CRISPR: Turning Fungus Blue (Well… Trying To!)

Hi! This post is going to be all about my CRISPR lab — the experiment where I tried to edit DNA to make a fungus turn blue instead of white. Basically, I used CRISPR to cut out a piece of DNA and replace it with something new.

There are four main stages in this experiment:
1️⃣ One week before
2️⃣ Three days before
3️⃣ One day before
4️⃣ The day of the lab

Here’s what it’s supposed to look like when it works:
(insert photo of the blue fungus)

Let’s go step by step!

A. Make the Plates

Day 1 observations:
This part was actually pretty easy — so don’t sweat it!

First, I warmed up some distilled water and added LB agar powder. I swirled it around and microwaved it in 30-second increments until it just started to boil.

Then I added ChIX (which I like to call “CheX Mix”), gave it another swirl, and mixed in the LB agar solution. Finally, I poured everything into Petri dishes.

They looked like little science pancakes!

B. Rehydrate the Bacteria

Next, it was time to wake up the bacteria.

I uncapped the vial of lyophilized bacteria (basically dried-out bacteria) and added LB + ampicillin. Then I closed the vial and gently flicked it to mix everything.

After that, I pipetted 50 μl of the rehydrated bacteria into 16 microtubes and left them to incubate at room temperature for about two days.

The key here: don’t disturb them! They’re busy doing microscopic magic.

C. Add CaCl₂ to the Bacteria 🧂

After the bacteria had some time to grow, I added 25 μl of CaCl₂ (that’s calcium chloride) to each tube. This helps prepare the bacteria to take in new DNA.

Then I put the tubes in the refrigerator to chill for 12–24 hours.
The best results happen after about 12 hours — but I let them chill overnight just to be sure!

D. Prep the Supplies & Equipment

Now for the fun part — understanding what’s actually happening!

Inside the DNA, there’s a special section called the LacZ gene. Normally, this gene helps make a blue protein. Here’s what’s cool:

• The RNA comes in and copies that LacZ gene.

• The RNA sends the instructions to the ribosomes (the cell’s protein factories).

• The ribosomes use that info to make blue proteins — giving the fungus its color!

But in this experiment, I added Cas9 (the “molecular scissors”) along with a guide RNA that tells it exactly where to cut. Cas9 finds the LacZ gene and slices it — stopping the blue protein from being made.

That’s why, when it works, the colonies turn white instead of blue — because the LacZ gene got knocked out!

If you want to see the full knockout guide I used, here’s the link:
👉 CRISPR Knockout PDF

Final Thoughts 💡

This experiment helped me understand how gene editing actually works. It’s wild to think that by using CRISPR, scientists can change how organisms look, act, or even glow!

Even if not everything turned out perfectly, it was amazing to learn what’s really happening inside the DNA.

Next time, I want to try again — but this time make sure my blue fungus really turns blue!