Embodiments of a method and/or system can include generating a set of target-associated molecules (e.g., spike-in molecules) associated with one or more biological targets; generating one or more spike-in mixtures based on processing the set of target-associated molecules with one or more samples including the one or more biological targets; performing one or more Sanger sequencing operations on the one or more spike-in mixtures; determining one or more abundance metrics based on chromatogram-related outputs from the one or more Sanger sequencing operations; and/or facilitating characterization of one or more medical conditions based on the one or more abundance metrics.