Blister pouches for effective reagent storage on microfluidic chips for blood cell counting

We present the analysis of blister pouches for reagent storage and release into microfluidic devices towards point-of-care blood cell counting applications. Blister pouches provide an effective reagent storage mechanism and can be mounted onto microfluidic cartridges directly. Reagents can be released from blister pouches through automated or manual compression and consequent rupturing of the pouches. A microfluidic device for metering of blister pouch contents was developed and investigated as part of this work, as precise volumes of reagents are often required when performing reactions, and particularly for blood cell counting applications which are the focus of this study. The metering device shows high accuracy and repeatability with an error of 1.93% and standard deviation of 3.1% across 30 test results. This work also investigates important blister pouch characteristics for three different types of blister pouch foil materials, including forces required to burst the blister, as well as shelf life and reagent compatibility of the blisters. Typical forces required are in the range of 25–35 N depending on the blister foil material used. Blister shelf life can be greatly affected by the reagent being stored, and thus, the blister foil material choice is crucial. This work provides a clear understanding of the implementation required to ensure that the blister pouches can be effectively used on microfluidic chips, with an example application area being point-of-care diagnostics.