FAQs

What is Electroendosmosis (EEO) in agar products and why does it matter for biotechnology?

Electroendosmosis (EEO) is a physical phenomenon triggered by ionized, negatively charged groups—specifically sulfate and pyruvic acid residues—fixed within the immobilized agar gel matrix. During gel electrophoresis, when an electrical field is applied, these fixed negative charges pull positively charged water ions (hydronium ions) toward the negative cathode, creating a counter-current internal water flow. For molecular biology applications like DNA or RNA separation, high EEO causes severe band distortion, sample smearing, and trailing. Consequently, premium electrophoresis-grade agarose must be strictly processed to a low-EEO rating (typically 0.05 to 0.13) by stripping away all trace agaropectin.