Does Freund's adjuvant denature protein antigens? EPR studies of emulsified hemoglobin

Use of complete Freund's adjuvant for production of antibodies to study protein conformation is valid only if emulsification in adjuvant does not denature protein antigens. Using electron paramagnetic resonance to observe directly the protein in situ in the opaque emulsions, we demonstrate that hemoglobin is not denatured by emulsification or storage in adjuvant for 24 hr at 4 degrees C, conditions comparable to the usual handling of antigens before immunization.