Hi

you can easily purify your generated mABs by SEC-HPLC with a very good recovery , also you can use native PAGE for the same purpose.

I would suggest to run again SDS-PAGE with the same preparations to see if this additional band of light chain with higher MW shows up again. Highly purified mAb should have only one sharp band as the light chain. Polyclonal Abs usually show a smear at the spot ~ 25K where the light chain is detected. If you see this additional sharp band is reproducible, you probably need to think about sub cloning of this hybrydoma cell line, because it might be contaminated with some other Ab cell line.

Hi

The additional band mean there are remaining relevant proteins, you can improve the purity by optimize wash step or add purification method

Thanks all for your answer, I switched my media to hybridoma media in the early stages of passaging (serum free) and this helped solved the problem. :)