Subcellular imaging of isotopically labeled carbon compounds in a biological sample by ion microprobe (NanoSIMS)
✍ Scribed by Peta L. Clode; Richard A. Stern; Alan T. Marshall
- Publisher
- John Wiley and Sons
- Year
- 2007
- Tongue
- English
- Weight
- 728 KB
- Volume
- 70
- Category
- Article
- ISSN
- 1059-910X
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✦ Synopsis
Abstract
Here we demonstrate the technique of nanoscale secondary ion mass spectrometry, utilizing the Cameca NanoSIMS50® ion microprobe, to detect and image the metabolism of an isotopically labeled compound (NaH^13^CO~3~) in a biological sample. In particular, we have designed and verified protocols for imaging the subcellular distribution and determining the relative abundance of labeled ^13^C, within the coral Galaxea fascicularis. Analyses were conducted on 1‐μm thick sections of resin‐embedded material, using both scanned (mapping) and static (spot analysis) Cs^+^ primary ion beam of ∼100 nm diameter. Using these samples we establish that NanoSIMS has adequate mass resolution to reliably distinguish ^13^C from potential isobaric interference by ^12^C^1^H and that data extracted from ion maps are comparable to those acquired by spot analyses. Independent of the method of acquisition, ratioing of ^13^C to the naturally abundant ^12^C is essential if meaningful data, which can be statistically compared to standard and control samples, are to be obtained. These results highlight the potential of NanoSIMS for intracellular tracking of a variety of organic and inorganic compounds labeled with stable isotopes of C, N, O, S, P, and halogens. Microsc. Res. Tech., 2007. © 2007 Wiley‐Liss, Inc.