Hello,

I am new to working with S. pneumoniae and its phages. Since studies on phages infecting S. pneumoniae are limited, I would like to know the best media for a double-layer assay. Specifically, what should the bottom and top layers consist of?

In our lab, we typically grow the bacteria on TSA with 0.8% sheep blood. For the double-layer assay, we tried using this as the bottom layer and BHI with 0.7% agar as the top layer, but no bacterial lawn formed. Could you help me solve this problem?

Thank you in advance.