RESUMO
Thymus- and activation-regulated chemokine (TARC, also known as CCL17) is used as a biomarker for atopic dermatitis. The methods currently used for its measurement are complex, time-consuming, and require large machinery, warranting the need for a method that is simple, has a quick turnaround time, and requires less complex machinery. We evaluated the analytical performance of a novel latex turbidimetric immunoassay method, "Nanopia TARC", on 174 residual serum samples from patients with skin or allergic diseases. This evaluation included the assessment of the limit of blank/detection/quantification (LOB/D/Q), precision, accuracy, linearity, interference, and commutability between Nanopia TARC and "HISCL TARC", based on the chemiluminescent enzyme immunoassay (CLEIA) method. The LOB/D/Q values were 13, 57, and 141 pg/mL, respectively. The coefficient of variation of the repeatability was 0.9-3.8%, and that of the intermediate precision was 2.1-5.4%. The total error of the accuracy was 1.9-13.4%. The linearity was 141 and 19,804 pg/mL for TARC. The correlation coefficient between Nanopia TARC and HISCL TARC determined using the Passing-Bablok regression analysis was 0.999. Furthermore, the concordance of diagnostic criteria with AD was 92%. Nanopia TARC was confirmed to have the same analytical performance for TARC measurement as the existing CLEIA method.
RESUMO
Coherent anti-Stokes Raman scattering (CARS) spectroscopy is a powerful tool for Raman imaging technology. In contrast, conventional spontaneous Raman spectroscopy is often used for biological analysis with multivariate analysis. This study develops a new type of CARS instrument with a double-wavelength-emission, background-free, electronically tuned Ti:sapphire laser (DW-ETL). DW-ETL generates two laser pulses with different wavelengths simultaneously within its single resonator. The pulse wavelength and buildup time are regulated by acousto-optical tunable filter in the resonator. The present DW-ETL CARS system is free from any mechanical movement to measure a CARS spectrum by controlling each laser pulse of the emission throughout the fingerprint region. Consequently, it is theoretically able to provide stable CARS spectra to apply multivariate analysis in biological applications. The present study demonstrates that the DW-ETL CARS system provides spectra of biomedical samples in the full finger-print region, and the stability and controllability of the system are evaluated.