Low-Cost Lateral Flow Dispenser System for Manufacturing Rapid Test Kits

The lateral flow test (LFT) is widely used in point-of-care diagnostics. Since COVID-19 pandemic, many companies and research groups started to develop their LFT due to its spectacular advantages: quick, compact, friendly user, and economical. The LFT manufacturing process requires expensive equipment to dispense antibody/antigen reagents across an absorptive surface which is unaffordable to a small laboratory in developing countries. In this work, we propose a low-cost Do-It-Yourself (DIY) LFT dispenser that keeps the quality like a commercial product. The LFT dispenser includes a Harvard Apparatus Model syringe pump which can control the dispensing antigen/antibody volume, manually, and a needle control part is connected to the syringe pump by a connector wire that includes a controllable step motor (Nema 17) and a linear actuator. The needle is attached to the linear actuator and moves across a straight line on a nitrocellulose (NC) membrane. By controlling the syringe pump and needle control simultaneously, the width of the antibody/antigen line is varied. There are two methods to dispense the antibody/antigen: filling the syringe with antibody/antigen and utilizing the air in the syringe to push the fluid out that helps minimizing antibody/antigen. The most optimal parameters of the first method to give a standard line (1 mm width) are syringe pump speed: 1−2 ml/h and needle control speed: 4.5–4.7 rev/s, and for the second method are 10–15 ml/h and 4.5–4.7 rev/s. We successfully demonstrated a low-cost ($500) LFT system that performs stably and correctly which is suitable for small laboratories in a developing country like Vietnam.