How do I interpret the reported uncertainty in my SEC-MALS experiment?

The reported uncertainties in ASTRA are statistical only, and do not include any of the many possible systematic errors that may be present. Examples are errors in dn/dc, the light scattering calibration constant, the RI and/or UV calibration constants, and the normalization coefficients.  Use the reported uncertainties as a measure of the statistical consistency of the data, never as an absolute limit on the error in your results.  Generally, we consider error less than 2% to be “good.”