A Multi‐Volume Microfluidic Device for Automated and Wide Dynamic Range Digital LAMP Applications

Abstract Digital nucleic acid quantification has emerged as an exceptionally valuable technique in molecular diagnosis, capturing significant attention in the biomedical field. This study introduces a novel multi‐volume digital loop‐mediated isothermal amplification (dLAMP) chip that offers an extensive detection range and user‐friendly operation. The chip consists of 1024 large chambers with the volume of 7.2 nL and 6400 small chambers with the volume of 0.064 nL. The ingenious combination of chambers with volume difference beyond a 100‐fold on the single chip enables a broad dynamic range exceeding 10 ⁵ for nucleic acid quantification. Furthermore, this chip incorporates an automated strategy, enabling the rapid loading and partitioning of the reaction mixture into subvolumes within 4 min. In order to evaluate the quantitative capability of the multi‐volume dLAMP chip, a 10‐fold serial dilution of the β‐actin DNA template is measured. Additionally, the chip is tested for β‐actin DNA concentration in plasma samples from colorectal cancer patients and healthy individuals. By providing enhanced automation, wide dynamic range, and improved accuracy, this chip paves the way for broader applications and the advancement of biomedical research fields.