Assessment for quantification of biopharmaceutical protein using a microvolume spectrometer on microfluidic slides

Spectrophotometric procedure is a traditional method for quantifying protein concentration in solution. The benefit of this method is simple and direct, not requiring standard materials, sample incubation, and exogenous chromophore addition. There are also some drawbacks, low detection limits and high amounts of protein needed. The recent advances in fiber optics and nano-technology enable to overcome those drawbacks by using microvolume sampling and extremely short pathlengths. In this study, the utility of the microvolume system with microfluidic carriers was assessed for concentration measurement of biopharmaceutical protein using absorbance at 280 nm and also compared to a traditional instrument. The results show a high correlation of estimation by Cohen’s d effect size and Pearson correlation coefficient between two different spectrometers. For UV spectral analysis, there are no statistically significant difference between those spectra from a microvolume spectrometer and a traditional one. For the extinction coefficient determination, two different spectrometers also give quite comparable and similar values. Thus a microvolume spectrometer can be used as an alternative over a traditional one to determine the concentration of biopharmaceutical protein. Moreover, the dynamic range for protein quantification by a microvolume spectrometer is over 10-fold higher than that of a traditional one.