streptomycin units

strep·to·my·cin u·nits

1. G unit: equals 1 g of the crystalline material or about 1,000,000 S units;
2. L unit: equal to 1000 S units;
3. S unit: the amount of streptomycin that will inhibit the growth of a standard strain of Escherichia coli in 1 mL of nutrient broth or other suitable medium.