IgG separation - (Sep/25/2007 )

hello every one,
i have separated IgG molecule and i runed on SDS-PAGE i have got 2 bands one at 25 kda that is light chain and 50kda ie heavy chain. now i need to separate light chain from each other.can i know which is the best technique for separation of thes light chain which have same molecular weight.

thanks in advace.
ali.

the light chains should be identical.