IQPrep Kit: A milli-fluidic test kit for immunodiagnostics

Abstract

Conventional laboratory-based diagnostics require highly sophisticated equipment to multiplex and analyze samples at scale. Recent advances in Point-of-care diagnostic devices have enabled rapid and accurate diagnosis on site leading to timely confirmation and effective management of individual and community health. A key enabler of such advancements is the simple to use lateral flow immunoassays that provide quick and accurate qualitative and semi-quantitative results. Typical lateral flow tests have sample preparation steps before deposition on the test membrane. Sample preparation by manual means is time-consuming and error-prone. The iQPrep Kit handles sample preparation using milli-fluidic channels and utilizes lateral flow test kits to quantitatively evaluate key immunological markers like HbA1c, Vitamin D, and TSH. The test kit design enables quick prototyping using 3D printing and can easily be mass-produced using injection molding. The functional performance of the kit was verified using a pneumatic system. The average fluid loss during fluid transport is around 7 µl using the pneumatic system. Repeatability tests were done to check if comparable amounts of fluid were transported for the same operating conditions. The coefficient of variation for the above test ranged between 2.1 % and 5.6 %. A quadratic relation was obtained between the fluid flow rate and the syringe air pressure for the multi-material valves within the kit. The quadratic fit had R2 values of 0.996 and 0.977 for the multichannel and dispensing valves, respectively. The multichannel and dispensing valves can withstand syringe air pressure of up to 2.1 kPa and 1.9 kPa, respectively, during fluid flow, before leaking. When the valves are closed, they can withstand a pressure of 1.3 kPa for 2 sec. An HbA1c test was done by manual sample preparation and using the kit. The results were similar in both cases establishing the accurate sample preparation capability of the kit. The iQPrep Kit is hence, a versatile test platform for immunodiagnostics.