Saliva offers many advantages for point-of-care (PoC) diagnostic applications due to non-invasive, easy, and cost-effective methods of collection. However, the complex matrix with its non-Newtonian behavior and high viscosity poses handling challenges. Several tedious and long pre-analytic steps, incompatible with PoC use, are required to liquefy and homogenize saliva samples before protein analysis can be performed. We apply magnet-beating to reduce hands-on time and to simplify sample preparation. A magnet in a chamber containing the whole saliva is actuated inside a centrifugal microfluidic cartridge by the interplay of centrifugal and magnetic forces. Rigorous mixing, which homogenizes the saliva sample, is then initiated. Consequently, fewer manual steps are required to introduce the whole saliva into the cartridge. After 4 min of magnet-beating, the processed sample can be used for protein analysis. The viscosity of whole saliva has been reduced from 10.4 to 2.3 mPa s. Immunoassay results after magnet-beating for three salivary periodontal markers (MMP-8, MMP-9, TIMP-1) showed a linear correlation with a slope of 0.99 when compared to results of reference method treated samples. Conclusively, magnet-beating has been shown to be a suitable method for the pre-analytic processing of whole saliva for fully automated PoC protein analysis.

BioVendor Laboratorní medicína a s Research and Diagnostic Products Division Karasek 1767 1 Reckovice 62100 Brno Czech Republic

Hahn Schickard Georges Koehler Allee 103 79110 Freiburg Germany

Laboratory for MEMS Applications IMTEK Department of Microsystems Engineering University of Freiburg Georges Koehler Allee 103 79110 Freiburg Germany

Section of Periodontology and Dental Prevention Division of Oral Diseases Department of Dental Medicine Karolinska Institutet Alfred Nobels Allé 8 14104 Huddinge Stockholm Sweden

University of Veterinary and Pharmaceutical Sciences Brno Faculty of Pharmacy Palackeho trida 1946 1 61242 Brno Czech Republic

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ImmunoDisk-A Fully Automated Bead-Based Immunoassay Cartridge with All Reagents Pre-Stored

OralDisk: A Chair-Side Compatible Molecular Platform Using Whole Saliva for Monitoring Oral Health at the Dental Practice