Combined Imaging and Chemical Sensing of Fertilization-Induced Acid Release from Single Sea Urchin Eggs

✍ Scribed by Karri L. Michael; David R. Walt

• Publisher: Elsevier Science
• Year: 1999
• Tongue: English
• Weight: 853 KB
• Volume: 273
• Category: Article
• ISSN: 0003-2697
• DOI: 10.1006/abio.1999.4173

✦ Synopsis

We demonstrate a microarray sensor capable of obtaining both chemical and visual information on multiple cells simultaneously with single-cell resolution. The array was fabricated by covalently immobilizing a thin, pH-sensitive polymer layer on the distal end of an optical imaging fiber. The sensor's ability to measure localized chemical dynamics in real-time was evaluated using sea urchin fertilization biochemistry as a model system. Following sea urchin fertilization, the Na ؉ /H ؉ transporter is activated to exchange extracellular sodium ions for intracellular hydrogen ions, causing a release of hydrogen ions at the egg's surface. By placing the pH sensor proximal to the egg and switching between a fluorescence image and a white light image, we were able to observe both localized pH changes following fertilization as well as morphological transformations during cell division.