for 10% resolving gel, i use a constant voltage of 120V. i keep the current variable dependent of the inherent property of the gel. around 130min of transfer gives me perfect result.

but make sure, you keep a cool pack within the transfer setup.

Hi,

In semi- dry transfer apparatus we mostly use 20V for 30 mins ..... 

Dear Adhab,

I use semi-dry blotter to transfer proteins to PVDF. The current (mA) is equal to the L (length of PVDF)X B (Breadth) X Current at cm-2. For example, if L= 4 cm, B= 3 cm, then current should I use = 3X4X0.8(Current at cm-2) = 9.6 mA for 2 h.

 Thank you all for your helpful input. 

If you hare using wet transfer (i.g. Biorad) it should run on 400mA (constant) for 1 hour (keep cold). However, today there are devices that enable rapid transfer (less than 10 minutes).

Good luck.