Organelle-specific intracellular oxygen measurements using iridium complex probes

2014 Fiscal Year Final Research Report

• Project/Area Number: 23310157
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Chemical biology
• Research Institution: Gunma University
• Principal Investigator: TOBITA Seiji 群馬大学, 大学院理工学府, 教授 (30164007)
• Co-Investigator(Kenkyū-buntansha): YOSHIHARA Toshitada 群馬大学, 大学院理工学府, 助教 (10375561)
• Project Period (FY): 2011-04-01 – 2015-03-31
• Keywords: 酸素プローブ / イリジウム錯体 / 低酸素 / りん光 / ミトコンドリア

Outline of Final Research Achievements

We synthesized new phosphorescent iridium complexes BTQ-Mito, BTQSA and BTQDM which are internalized into biological cells without any transfection reagents and show specific localization to mitochondrion, endoplasmic reticulum (ER) and lysosome, respectively. These complexes exhibit oxygen-dependent phosphorescence in living cells. Phosphorescence lifetime measurements of living HeLa cells stained with these probes under a microscope enabled us to examine the subcellular oxygen status. The phosphorescence lifetimes of these probes internalized in HeLa cells were calibrated for the oxygen partial pressure of an incubator according to Stern-Volmer analyses, providing the oxygen quenching rate constant and the average lifetime in the absence of oxygen. Using the values of the oxygen quenching rate constant and the average lifetime, the oxygen level of HeLa cells was evaluated by lifetime measurements.

Free Research Field

光化学