Table of Contents
ISRN Molecular Imaging
Volume 2013 (2013), Article ID 689279, 7 pages
http://dx.doi.org/10.1155/2013/689279
Research Article

Subcutaneous Administration of D-Luciferin is an Effective Alternative to Intraperitoneal Injection in Bioluminescence Imaging of Xenograft Tumors in Nude Mice

1Department of Otolaryngology-Head and Neck Surgery, University of Virginia Health System, P.O. Box 800713, Charlottesville, VA 22908-0713, USA
2Department of Biochemistry, National Liver Institute, Menoufiya University, Shebin Elkom 32511, Egypt
3Department of Neurosurgery, Virginia Commonwealth University, Richmond, VA 23298, USA
4Department of Radiation Oncology, Georgia Health University, Augusta, GA 30912, USA
5Department of Radiation Oncology, Virginia Commonwealth University, Richmond, VA 23298, USA

Received 27 August 2013; Accepted 27 October 2013

Academic Editors: H. Hendrikse and P. Lass

Copyright © 2013 Ashraf A. Khalil et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Currently, intraperitoneal (IP) injection of D-luciferin is the preferred method of providing substrate for bioluminescence imaging (BLI); however it has a failure rate of 3–10% due to accidental intestinal injection. The present study evaluates the quality of BLI after subcutaneous (SC) injection of D-luciferin and demonstrates the effectiveness of SC injection in anatomically disparate tumor models. Mice bearing luciferase-expressing tumors underwent BLI after SC or IP injection of D-luciferin. The average time to maximal luminescence was 6 min (range 5–9 min) after SC injection and 8 min (range 5–8 min) after IP injection. Within 7 minutes of injection, SC and IP routes yielded similar luminescence in subcutaneous, intracranial, tongue, and lung xenograft tumor models. In a model of combined subcutaneous and intracranial xenografts, SC injection resulted in proportional luminescence at all sites, confirming that preferential delivery of substrate does not occur. While tumors were occasionally not visualized with IP injection, all tumors were visualized reliably with SC injection. Thus, SC injection of D-luciferin is a convenient and effective alternative to IP injection for BLI in nude mice. It may be a preferable approach, particularly for tumors with weaker signals and/or when greater precision is required.