gamma globulin and Dnase I

[rasing02]

I want to prepare 1mg/ml stock of γ-Globulins from bovine blood

as a standard for Bradford's assay, I dont know if I should dissolve the powder in distill water or some buffer? Please guide me with the same.

 

I also want to prepare 25U/ml Dnase I and add it in my lysis buffer to lyse proteins. I have a powder form of Dnase which mentions it is 20000 U and wt is 4.12g, I am confused about how to prepare a stock of 25U/ml and I should dissolve the enzyme in what type of solution? water or some buffer or glycerol???

[CharonY]

1) If you prepare things for immediate measurement, they easily water soluble (but not stable if stored in it). Ideally you should use the same buffer as you are going to use for your real sample for Bradford.

 

2) If 4.12g are 20,000 U how much g corresponds to 1U? You should use a buffer that ensure DNAseI activity. A common one is Tris pH 7.6 with MgCl2 and CaCl2 (2.5 and 0.5 mM if I recall correctly).

For storage, however Tris with 50% glycerol and CaCl2 is generally used.