NEFL and amyotrophic lateral sclerosis: Nf-L levels measured in elutes from 13 DPS obtained using Noviplex cards microsampling (Np-DPS), inclusive of healthy controls as well neurological controls and ALS patients, showed a high correlation with Nf-L levels measured in the same volume of matched plasma samples (p < 0.0001; R2 0.9) (Fig. 3C.1).