DNase Test HiCynthâ„¢ Agar w/Toluidine blue is recommended for the detection of deoxyribonuclease activity of bacteria and fungi, and especially for identification of Staphylococci. With added toluidine blue, it is used in differentiation and identification of non-pigmented Serratia species isolated from clinical sources that might be improperly identified as Enterobacter and Klebsiella species. This medium is prepared by replacing animal peptones with vegetable defined peptones to avoid BSE/TSE/GMO risk.