Published online by Cambridge University Press: 07 September 2010
INTRODUCTION
Reporter genes (RGs), an integral part of molecular imaging, have become essential tools for studying biology in living subjects noninvasively. Currently, molecular imaging techniques can be broadly classified into five categories based on the spectrum and source of energy used for detection. These are optical imaging (fluorescence and bioluminescence imaging), radionuclide imaging (positron emission tomography (PET) and single photon emission computed tomography (SPECT), X-ray computed tomography imaging (CT), magnetic resonance imaging (MRI), and ultrasound (US) imaging. Excluding CT and US, a variety of reporter genes have been developed for the remaining three categories, which can be used to study specific biological processes (such as promoter activation, transcription, translation, protein–protein interaction) and monitor disease progression and therapy (Figure 5.1). Reporter genes therefore are also categorized into different groups based on their usage for different imaging techniques.
REPORTER GENES
Optical Reporter Genes
By definition, an optical reporter protein can emit light in the visible range (300 nm–600 nm) either by interacting with specific substrates (luminescence) or by being excited with light of specific wavelength (fluorescence). The emitted light can then be captured in a sensitive charge coupled device (CCD) camera and presented as an optical signature. Both luminescence and fluorescence reporter genes have advantages and disadvantages that carry over to their in vivo imaging instrumentation and their application to noninvasive imaging. The luminescent reporter genes are commonly known as luciferases. Luciferase proteins (translated from luciferase genes) were originally isolated from different beetles, bacteria, and marine organisms.
To save this book to your Kindle, first ensure [email protected] is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Find out more about the Kindle Personal Document Service.
To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Dropbox.
To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Google Drive.