Instill Science
home about spaces
sign up

Instill Science

A place to discuss science, share work, and find mentors and collaborators

Instill Science / Top Agar Question
April 6, 2023 ∙ bob-kuhn
Top Agar Question

This is a basic question but one I do need advice with. My high school phage team will begin looking for a phage next fall from a new host. The host has not been studied much for phages. How do you choose a top agar for new hosts/phages? Is there a generic TA that works well? We currently use MBTA for Mycobacterium but I did not know if top agars are phage specific. Thanks for your guidance.

Loading ...
jessica-sacher ∙ April 14, 2023 ∙
Hmm, good question! in my experience I've always just added agar powder (to final w/v of around 0.6%) to whatever growth medium my bacteria likes. For example when I'd use BHI agar plates for Campylobacter phage work, I'd make BHI top agar to layer on top of it. I also used to add CaCl2 and MgCl2 (something like 1 mM CaCl2 and 10 mM MgSO4 -- https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0116287) to both my BHI bottom agar + top agar. But essentially I'd default to whatever the bacteria likes best, plus maybe some Ca / Mg if the phage likes that.