Tehran University of Medical Sciences Iranian Journal of Allergy, Asthma and Immunology 1735-1502 17 4 2018 08 12 326 335 EN Sorour Shojaeian Department of Biochemistry, Medical Genetics, Nutrition, Alborz University of Medical Sciences, Karaj, Iran Abdolamir Allameh Department of Clinical Biochemistry, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran Mahmood Jeddi-Tehrani Department of Hybridoma, Monoclonal Antibody Research Center, Avicenna Research Institute, Academic Center for Education, Culture and Research (ACECR), Tehran, Iran Roya Ghods Oncopathology Research Center, Iran University of Medical Sciences, Tehran, Iran AND Department of Molecular Medicine, Faculty of Advanced Technologies in Medicine, Iran University of Medicine Sciences, Tehran, Iran Jaleh Shojaeian University of Maryland School of Pharmacy, Baltimore, Maryland, USA Akram-Sadat Tabatabaei-Panah Department of Biology, Faculty of Basic Sciences, Islamic Azad University, East Tehran Branch (Ghiamdasht), Tehran, Iran Amir-Hassan Zarnani Department of Immunology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran AND Reproductive Immunology Research Center, Avicenna Research Institute, ACECR, Tehran, Iran AND Immunology Research Center (IRC), Iran University of Medical Sciences, Tehran, Iran 2017 08 01 2018 02 13 In recent years, a lot of attention has been paid to quantum dot (QD) nanoparticles as fluorescent sensors for sensitive and accurate detection of cancer biomarkers. Here, using a homemade specific monoclonal antibody against CA125 and QD525- or FITC-labeled probes, expression of this marker in an ovarian cancer cell line and cancer tissues were traced and optical properties of fluorophores were compared qualitatively and quantitatively. Our results clearly showed that besides lower background and exceptionally higher photobleaching resistance, QD525 exhibited higher fluorescent intensity for both ovarian cancer cell and tissues at different exposure times (p<0.0001) and excitation filter sets (p<0.0001) exemplified by significantly higher staining index (p<0.016). More importantly, the FITC-labeled probe detected antigen-antibody complex at minimum concentration of 0.3 mg/mL of anti-CA125, while reactivity limit decreased to 0.078 mg/mL of anti-CA125 when QD525-labeled probe was applied showing four times higher reactivity level of QD525 probe compared to the same probe labeled with FITC. Based on our results, it seems that QDs are inimitable tags for sensitive detection and localization of ovarian cancer micrometastasis and molecular demarcation of cancer tissues in surgical practice, which subsequently figure out accurate therapeutic approaches.  https://ijaai.tums.ac.ir/index.php/ijaai/article/view/1603 https://ijaai.tums.ac.ir/index.php/ijaai/article/download/1603/840