Fig. 2
![Fig. 2](http://media.springernature.com/full/springer-static/image/art%3A10.1186%2Fs13195-021-00939-9/MediaObjects/13195_2021_939_Fig2_HTML.png)
Parallelism of the six P-tau assays. Serial dilution of four plasma samples (in green, solid lines) and one calibrator (in purple, dashed line) was performed for each of the P-tau assays. Plasma samples with relatively high endogenous P-tau concentrations were selected for the parallelism experiment. For P-tau231 Gothenburg, one sample showed no signals upon dilution for the 8- and 16-fold dilutions. Crosses represent the individual measurements. A linear slope was fitted for each sample and for the calibrator, the equation of which is presented in the figures