Rapid detection of HIV-1 p24 antigen using magnetic immuno-chromatography (MICT)

Detection of human immunodeficiency virus (HIV) infections has been enhanced by incorporating p24 antigen detection with current HIV antibody detection using enzyme immunoassays (EIAs). However, screening for HIV antibodies has increased through the use of rapid, lateral-flow HIV antibody detection assays that currently do not have the capability to detect HIV p24 antigen. In this report, a lateral-flow based assay using super-paramagnetic particles as the detection marker was developed for the detection of HIV-1 p24 antigen. This magnetic immuno-chromatographic test (MICT) uses an inexpensive, low-maintenance instrument that detects the magnetic moment of the super-paramagnetic particles in a magnetic field. MICT is simple to perform, provides a numerical output for easier determination of reactive results and can be completed in 40 min. The lower limit of detection for HIV-1 p24 spiked into assay sample buffer and 50% plasma was 30 pg/ml for both. Detection of HIV-1 p24 antigen at 50 pg/ml was reproducible in both inter-run and intra-run assays with coefficients of variation of