A Pocketed Immunoblotting Disc for Field-Deployable Profiling of Multiantibody Spectrum

Rapid profiling of an unexpected blood group antibody spectrum plays a critical role in emergency medicine. However, field-deployable profiling still remains elusive due to the requirement of tedious erythrocyte sensitization and multistep result readout procedures. Therefore, we invented a pocketed immunoblotting disc assay (PiDa) capable of rapidly profiling multiple unexpected antibodies in a field-deployable manner. First, we constructed a molecular reaction microenvironment by devising a cotton linter@polyethylene glycol-modified hydrogel sticker to accelerate molecular collision within a confined three-dimensional microwell mesh, realizing ultrafast erythrocyte-IgG antibody agglutination within 2 min. Then, the hydrogel sticker was stamped onto a Blu-ray disc to form an immunoblot array; thereby, multiantibody signals could be read out within 5 min using a pocketed BD driver equipped with a machine learning algorithm. In a pilot study, the proposed PiDa successfully identified 28 unexpected antibody classes simultaneously within 8 min, which is 8 times faster than classical gel-card assays. Also, 100% accuracy was attained in analyzing 150 clinical blood samples, validating its feasibility in constructing a portable and versatile platform toward high-throughput biomolecular determination.