The Dual Role of Paramagnetic Particles for Integrated Lysis and Measurement in a Rapid Immunoassay for Intracellular Proteins

Abstract

A novel, integrated lysis and immunoassay methodology and system for intracellular protein measurement are described. The method uses paramagnetic particles both as a lysis agent and assay label resulting in a rapid test requiring minimal operator intervention, the test being homogeneous and completed in less than 10 min. A design study highlights the critical features of the magnetic detection system used to quantify the paramagnetic particles and a novel frequency-locked loop-based magnetometer is presented. A study of paramagnetic particle enhanced lysis demonstrates that the technique is more than twice as efficient at releasing intracellular protein as ultrasonic lysis alone. Results are presented for measurements of intracellular prostate specific antigen in an LNCAP cell line. This model was selected to demonstrate the rapidity and efficiency of intracellular protein quantification. It was shown that, on average, LNCAP cells contained 0.43 fg of prostate specific antigen. This system promises an attractive solution for applications that require a rapid determination of intracellular proteins.

Magneto-reactance based detection of MnO nanoparticle-embedded Lewis lung carcinoma cells

“…However, Sharif et al have recently shown that it is possible to quantify the paramagnetic particles having small magnetic moments by using a properly designed magnetic detection system. 15 Recently, we have demonstrated the high capacity of detecting low concentrations of $10 nm SPIO MNPs and biomolecules tagged to them using a magneto-reactance (MX) based biosensor. 2,7,13 The detection sensitivity of the MX-based biosensor has been reported to reach an extremely high value of 30%, which is about 4 times higher than that of a MI-based biosensor.…”