Pouring black agar plates. Look at the vanta black in that flask!

Pouring black agar plates. Look at the vanta black in that flask!

Today I horribly failed at pouring black agar plates.

Recipe: Black Agar Malt Extract Dextrose Medium (MEAD-C)

I adjusted the recipe as follows:

Lab-grade malt extract agar with charcoal (MEA-C), sufficient for 1 litre final volume of medium.

Add to ~800 mL distilled water. Stir to mix. Bring to final volume of 1000 mL. We recommend autoclaving then allowing to cool to the point where containers of the solution are warm, but cool enough to be handled safely. Swirl containers to ensure contents are well-mixed, and then pour/dispense by pipette into Petri plates or other containers in your flow hood or glove box. ~50 plates at ~20 ml/plate. This medium is black to increase visibility of light-coloured mycelia.

Blacked out agar solution looking shwifty.

Blacked out agar solution looking shwifty.

At this point the sealed dishes still looked good. After sterilising them in the pressure cooker for 20 min the Parafilm melted and left an ugly gooey mess.

At this point the sealed dishes still looked good. After sterilising them in the pressure cooker for 20 min the Parafilm melted and left an ugly gooey mess.

Unfortunately the activated charcoal powder turned out to bee way to coarse. Also for some reason the agar never fully set – maybe too little Agar-Agar powder. I will have to retry and adjust.