Pen/Strep from Sigma unit confusion - (Jul/22/2012 )

Dear all, I would like to ask about unit for Pen/Strep preparation from Sigma (P0781), 100 mL. On the label, the concentration is 10000 unit/10 mg/mL Pen/Strep. The 10000 unit of penicillin referred to the amount of penicillin present in 100 mL or the concentration (10000 unit/mL). Anyone can help me on this?

It is per ml, as the product sheet (and the website) says

It's 100X concentrate;

Streptomycin 10'000 μg/ml

Penicillin 10'000 Units/ml

By adding 1ml of this antibiotics solution to 100ml (99+1) medium you would have 100μg and 100 Units of Streptomycin and Penicillin, respectively.

Thank you all