A spectrophotometric procedure for DNA assay with a microsequential injection lab-on-valve meso-fluidic system

A micro-sequential injection spectrophotometric procedure for DNA assay was developed based on the employment of a lab-on-valve (LOV) meso-fluidic analytical system. A small amount of crystal violet solution (10 mu l) was de-colored inside the flow cell of the LOV at the presence of 5 mu l lambda-DNA/HindIII within a certain pH range, and the absorbance decrease of crystal violet solution at 591 nm was measured via optical fibers and was employed as the basis of quantification. A uni-variant approach was adopted for the optimization of experimental parameters, including buffer pH, concentration and volume of crystal violet solution, reaction time and sample/reagent loading flow rates. A linear calibration graph was obtained within 0.2-6.0 mu g ml(-1), along with a detection limit of 0.07 mu g ml(-1). The procedure was applied for the determination of lambda-DNA/HindIII in synthetic samples in comparison with a documented procedure. (C) 2005 Elsevier B.V. All rights reserved.