A device for performing analyses in a microfluidic system comprising: a micro fluidic system formed in a substrate comprising a first micro fluidic channel (34, 112) including at least one inlet (36, 116) and one outlet (38, 118) and a second microfluidic channel (24, 158) including at least one inlet (26, 154) and one outlet, (28, 156), a reaction area that allows detection of a chemical and/or biological reaction in the reaction area, wherein the second microfluidic channel (24, 158) is in fluid communication with the reaction area; a fluidic connector (40, 178) that can be connected to the substrate, the fluidic connector comprising a fluid path including a fluid path inlet and a fluid path outlet, wherein upon connection, the fluid path inlet connects to the outlet of the first micro fluidic channel to allow fluid communication between the fluid path and the first microfluidic channel, and the fluid path outlet connects to the inlet of the second microfluidic channel to allow fluid communication between the fluid path and the second microfluidic channel, wherein the fluid path contains a sample disposed therein prior to connection of the fluidic connector to the substrate wherein the first microfluidic channel comprises a first reagent disposed therein prior to connection of the fluidic connector to the substrate, wherein the second microfluidic channel comprises a second reagent disposed therein prior to connection of the fluidic connector to the substrate, and wherein the first and second microfluidic channels are not in fluid communication with one another prior to first use, wherein the device is suitable for flowing the sample from the fluidic connector to the reaction area to interact with the second reagent before the first reagent flows to the reaction area via the fluid path. a micro fluidic system formed in a substrate comprising a first micro fluidic channel (34, 112) including at least one inlet (36, 116) and one outlet (38, 118) and a second microfluidic channel (24, 158) including at least one inlet (26, 154) and one outlet, (28, 156), a reaction area that allows detection of a chemical and/or biological reaction in the reaction area, wherein the second microfluidic channel (24, 158) is in fluid communication with the reaction area; a fluidic connector (40, 178) that can be connected to the substrate, the fluidic connector comprising a fluid path including a fluid path inlet and a fluid path outlet, wherein upon connection, the fluid path inlet connects to the outlet of the first micro fluidic channel to allow fluid communication between the fluid path and the first microfluidic channel, and the fluid path outlet connects to the inlet of the second microfluidic channel to allow fluid communication between the fluid path and the second microfluidic channel, wherein the fluid path contains a sample disposed therein prior to connection of the fluidic connector to the substrate wherein the first microfluidic channel comprises a first reagent disposed therein prior to connection of the fluidic connector to the substrate, wherein the second microfluidic channel comprises a second reagent disposed therein prior to connection of the fluidic connector to the substrate, and wherein the first and second microfluidic channels are not in fluid communication with one another prior to first use, wherein the device is suitable for flowing the sample from the fluidic connector to the reaction area to interact with the second reagent before the first reagent flows to the reaction area via the fluid path.