Rotary-based platform with disposable fluidic modules for automated isolation of nucleic acids.

Abstract

We describe the development and evaluation of a rotary-based platform with multiple disposable fluidic modules for simultaneous automatic nucleic acid (NA) isolation from up to 24 biological samples. The procedure is performed inside insulated individual disposable modules, which minimizes both the risk of infection of personnel and laboratory cross-contamination. Each module is a segment of a circular cylinder containing a leak-proof inlet port for sample input, reservoirs with lyophilized chemicals and solvents, fluidic channels, stoppers, valves, a waste reservoir and an outlet port equipped with the standard micro test tube for NA collection. The entire platform, apart from the rotor that accommodates 24 modules, consists of functional elements that provide spinning of the rotor, reagent mixing, pressure delivery, and heating of reaction mixtures. The transfer of the reaction mixtures inside the modules is performed either with rotation of the rotor or with excessive air pressure applied to the module's reservoirs. The entire process takes less than 40 min, starting from the sample loading to the recovery of the purified NA, and it allows NA isolation both from bacterial cells and viral particles. The feasibility and reproducibility of the developed platform was demonstrated by the NA isolation from suspensions of Bacillus thuringiensis and Mycobacterium tuberculosis cells within a concentration range of 10(8) to 10(2) cells/ml. Isolation of NAs from blood plasma samples with varying concentration of hepatitis B and C viruses from 10(7) to 10(2) particles/ml were also successful. The purity and integrity of the extracted NAs were both reliable for performing quantitative PCR.