Abstract: For ion-exchange expanded bed adsorption, the biomass (cells and cell debris) existing in the feedstock would adhere to the adsorbent, which certainly influence the bed stability and adsorption efficiency for the targets.With E.coli DH5α as the model biomass and Streamline DEAE as the typical anion exchanger for EBA, the influence of cell homogenization processes on the biomass/adsorbent interaction in expanded bed was investigated by using the biomass pulse-response experiments.The biomass transmission index (BTI) was used as a quantitative parameter for evaluating the biomass adsorption in expanded bed.The results indicated that more intense homogenization caused higher BTI and weaker biomass/adsorbent interaction, with smaller size of cell debris and lower zeta potential of homogenate.Based on the theory of electrostatic interactions, a good linear correlation was found between BTI and (-ζ_Aζ_Bd_B), which combined the influences of zeta potential of adsorbent (ζ_A), zeta potential of biomass (ζ_B) and biomass size (d_B).When -ζ_Aζ_Bd_B<100 mV²&#8226;μm, BTI response was more than 0.9, indicating no or very slight biomass/adsorbent interactions.This relation could be used to pre-evaluate the influence of biomasss and simplify the process design of EBA.