I am trying to find out the appropriate ELISA method to detect aflatoxin-lys from serum sample. I am facing problems with sample preparation before ELISA. Currently I am following the steps: 1. Isolation of alb from serum sample by ammonium sulphate 2. quantitation of alb by comassie protein assay 3. digestion of alb by pronase to get af-lys 4. ELISA to quantify the af-lys using AFB-lys as standard. But its not working well because I am having a lower level of alb from serum sample than expected or it may be other reasons. I would appreciate any help you all may be able to give me. Thanks in advance.