Immunocapture couples with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry for rapid detection of type 1 dengue virus

A facile method for accurate detection of type 1 dengue virus (DV1) infection from complex biological mixtures, using type specific immunocapture coupled with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), was developed. The biological mixtures were treated with magnetic particles coated with a monoclonal antibody directly against type 1 dengue virus. After immunocapture purification, the DV1 was eluted with 30% acetic acid, directly spotted with seed-layer method, and analyzed by MALDI-TOF MS for DV1 capsid protein. The detection limit of the assay was ∼105 pfu/mL by MALDI-TOF MS. The immunocapture could unambiguously differentiate the DV1 from other serotypes of the dengue viruses and Japanese encephalitis virus, and could be used as a specific probe to detect DV1 from complex biological mixtures.