SALAD: Syringe- based Arduino- operated Low-cost Antibody Dispenser
Point-of-care diagnostics, particularly Lateral Flow Assay (LFA), have been one of the most widely adopted technologies in clinical diagnosis over recent years, especially during the COVID-19 pandemic due to its feasibility, compactness, and rapid readout. However, their fabrication posed challenges for research groups with limited budgets. This study aimed to resolve one of the key issues in the fabrication process of LFA - antibody dispensing, by introducing a Syringe-based Arduino-operated Low-cost Antibody Dispenser (SALAD). This model can be self-manufactured at a lower cost ($200.61) compared to the commercialized models, expected to provide alternative approaches for researchers that are interested in LFA. By utilizing a microneedle small gauge (26G), stepper motors-driven syringe pump, and conveyor belt, SALAD can form micro-droplets to create an even band of antibodies. This study includes (1) the design of SALAD and (2) the evaluation of SALAD using food dye, antibody-[HRP] conjugates, and direct ELISA to test the stability of dispensed antibodies under capillary forces. The results showed comparable performance between SALAD and a commercialized model - Claremont ALFRD, with SALAD exceeding in affordability and feasibility. SALAD was able to yield an even signal, uniform bandwidth, and low background noise, yet optimization in the conveyor belt should be considered to enhance stability. This includes the CNC Cutting components files (STL), designed using the FUSION 360 Program, an Arduino Operation Code for the Syringe-based Arduino-operated Low-cost Antibody Dispenser (SALAD) and a MP4 video demonstrating how the Line Dispenser works.