Abstract: A method for characterizing the gene expressions of a sample of cells of a living subject, where the sample of cells is characterized by one or more marker sequences.

Abstract: Molecular beacon for detecting an infection and/or expression or a mutation of a disease marker for diagnostics and pharmacogenomics. The molecular beacon is capable of hybridizing a disease-related RNA or DNA of a disease marker in a specimen obtained from a living subject, thereby emitting a signal detectable without a need for signal amplification. The disease marker includes a genetic sequence specific to a pathogen including a flu virus, a cancer cell marker, and a drug resistance-related genetic mutation marker for a drug resistant cancer and infectious pathogen. To detect a disease cell, a specimen containing one or more cells is obtained from a living subject, and fixed by an organic solvent. A molecular beacon is then added to the specimen, followed by staining nuclei of the cells in the specimen. The signal is detectable with a microscope, FACS scan, ELISA plate reader, Scanner, or any combinations thereof.