Science Buddies: "Ask an Expert"

Can a test solution of snake venom be applied directly to a bacteria coated agar plate for antimicrobial studies, or do you have to use a sterile disk coated in the solution and then applying to the bacteria plate.

Scotty,
I would recommend using coated discs instead of just adding the venom to the plate. That will allow for the same amount to be added to your replicate plates and also will make the effectiveness easier to see (by measuring the zone of inhibition). Your project sounds very interesting, are you going to test the venom against pure cultures of specific species of bacteria?

That is what we did last year and now as well this year thanks. Yes, we are testing it against three pure cultures of bacteria. We are also hoping to test the solutions and fractions against the red blood cells too.

We are choosing to use sheep blood agar plates to test the hemolysis of the serial dilutions of the venom, do we have to incuabe the sheep blood agar plates if we arent trying to see bacterial growth?

Hi,

That might be helpful to incubate the plates. The bacteria and red blood cells typically grow best when incubated; even if you aren't measuring growth it would be nice to keep temperature consistent.