['To solve the problem of fixed dried blood spot elution without damaging IgG antibodies.', 'The minimum effective concentration of liquid ammonium (NH3 ) in a PBS solution, which was found to elute fixed blood, was determined. By using a dilution series, the effects of NH3 on IgG antibody quality were assessed using immunofluorescence assays.', 'The minimum effective concentration of 0.2% NH3 has no detectable effects on IgG quality.'] Does ammonium improve elution of fixed dried blood spots without affecting immunofluorescence assay quality?