Simultaneous calibration was validated by the tree-shaped
design (Fig. 5a). The left six assays provides a series of samples
with concentration from 0 to 2.5 mg/mL, the right assay is dotted
with sample of known concentration BSA with 0.75 mg/mL in the
artificial urine. Results can be obtained either from comparison of
the color by naked eyes or the intensities in the standard curve
made with Quantity One. With naked eyes, we observed in Fig. 4a
that the color intensity of the sample in artificial urine (the right
assay) was between that of the second and third left assays (that
is, between 0.5 and 1.0 mg/mL). With image software of Quantity
One, Fig. 5b demonstrates that the color intensity of the sample in
artificial urine reads 0.82 mg/mL in the software. The results were
consistent with the true value. Only with naked eyes, the accuracy
of judgment is determined by the step designed in the calibration.
From Fig. 4a, the homogeneous micro fluid situation could also be
validated by the phenomena of the same running distance BPB dots