A system for testing a biological subject includes an imaging device and an imaging agent detectable by the imaging device, for detecting amount and location of a biomarker in the biological subject. The imaging agent includes a fluorescent microsphere and a targeting member attached to the fluorescent microsphere. A method of testing a biological subject using the system includes providing the imaging agent, applying the imaging agent to a testing location of a patient and imaging the imaging agent in the testing location by the imaging device, so as to detect the amount and locations of the imaging agent. A method of screening and diagnose a cancer that is accessible via cavity of a patient, includes performing a CD44 and total protein test, and if the result is positive, performing an imaging test.
