|
Hi Tamara,
Read:
- Mol Imaging Biol. 2009 Dec 10. [Epub ahead of print]
A Comparison Between Time Domain and Spectral Imaging Systems
for Imaging Quantum Dots in Small Living Animals.
-
de la Zerda A,
Bodapati S,
Teed R,
Schipper ML,
Keren S,
Smith BR,
Ng JS,
Gambhir SS.
- Department of Radiology, Molecular Imaging Program at Stanford
(MIPS), The Bio-X Program, Stanford, CA, 94305, USA.
Abstract
- PURPOSE: We quantified the performance of time-domain imaging (TDI)
and spectral imaging (SI) for fluorescence imaging of quantum dots (QDs)
in three distinct imaging instruments: eXplore Optix (TDI, Advanced
Research Technologies Inc.), Maestro (SI, CRi Inc.), and IVIS-Spectrum
(SI, Caliper Life Sciences Inc.). PROCEDURE: The instruments were
compared for their sensitivity in phantoms and living mice, multiplexing
capabilities (ability to resolve the signal of one QD type in the
presence of another), and the dependence of contrast and spatial
resolution as a function of depth. RESULTS: In phantoms, eXplore Optix
had an order of magnitude better sensitivity compared to the SI systems,
detecting QD concentrations of ~40 pM in vitro. Maestro was the best
instrument for multiplexing QDs. Reduction of contrast and resolution as
a function of depth was smallest with eXplore Optix for depth of 2-6 mm,
while other depths gave comparable results in all systems. Sensitivity
experiments in living mice showed that the eXplore Optix and Maestro
systems outperformed the IVIS-Spectrum. CONCLUSION: TDI was found to be
an order of magnitude more sensitive than SI at the expense of speed and
very limited multiplexing capabilities. For deep tissue QD imaging, TDI
is most applicable for depths between 2 and 6 mm, as its contrast and
resolution degrade the least at these depths.
- PMID: 20012220
One problem with the paper is they did not do a fair comparison in
terms of exposure duration. One of the ART experiments included a 50
minute exposure, whereas the Maestrao and Xenogen were seconds. They also
did not appear to use the spectral unmixing capability of the IVIS
Spectrum.
They also failed to discuss that the Xenogen IVIS was initially designed
for firefly luciferase imaging - its cryogenic cooled back illuminated
CCD camera far outperforms the Carestream and Maestro cameras. That the
"Spectrum" features were added is a marketing issue - hopefully
your users will saturate the IVIS use in BLI.
With respect to luciferases, Brian Rabinovich has published a firefly
luciferase that is far superior to Promega's pGL3 (mainly because of
Brian hand optimized the sequence to eliminate splice sites - amino acid
coding sequence is the same). He has also made improved Gaussia and
Renilla luciferases. The original MTA was tedious but he has now been
allowed to simplify it to the end user including Brian as a coauthor on
all papers and letting Brian review/comment the manuscript(s) before it
goes out.
- Proc Natl Acad Sci U S A. 2008 Sep 23;105(38):14342-6. Epub 2008 Sep
15.
Visualizing fewer than 10 mouse T cells with an enhanced
firefly luciferase in immunocompetent mouse models of cancer.
-
Rabinovich BA,
Ye Y,
Etto T,
Chen JQ,
Levitsky HI,
Overwijk WW,
Cooper LJ,
Gelovani J,
Hwu P.
- M. D. Anderson Cancer Center, 7455 Fannin Street, Houston, TX 77054,
USA. [hidden email]
Abstract
- Antigen specific T cell migration to sites of infection or cancer is
critical for an effective immune response. In mouse models of cancer, the
number of lymphocytes reaching the tumor is typically only a few hundred,
yet technology capable of imaging these cells using bioluminescence has
yet to be achieved. A combination of codon optimization, removal of
cryptic splice sites and retroviral modification was used to engineer an
enhanced firefly luciferase (ffLuc) vector. Compared with ffLuc, T cells
expressing our construct generated >100 times more light, permitting
detection of as few as three cells implanted s.c. while maintaining long
term coexpression of a reporter gene (Thy1.1). Expression of enhanced
ffLuc in mouse T cells permitted the tracking of <3 x 10(4) adoptively
transferred T cells infiltrating sites of vaccination and preestablished
tumors. Penetration of light through deep tissues, including the liver
and spleen, was also observed. Finally, we were able to enumerate
infiltrating mouse lymphocytes constituting <0.3% of total tumor
cellularity, representing a significant improvement over standard methods
of quantitation including flow cytometry.
- PMID: 18794521
My friend Mike Rosol runs a small animal imaging core -
http://hcc.musc.edu/research/sharedresources/smallanimalimaging.htm
has his equipment:
Equipment:
- Currently, the HCC Small Animal Imaging Facility has a Caliper Life
- Sciences IVIS 200 small animal optical imaging device, a Siemens
- Inveon micro-CT/PET, and access to a shared Bruker 7T MRI. The
- following are the main instruments housed in the HCC:
- Xenogen/Caliper Life Sciences IVIS 200 Bioluminescent
Imaging System
- The IVIS 200 is capable of imaging up to 5 animals at a time and is
- also capable of providing limited 3-D depth information. The imaging
- system consists of an enclosed, heated container containing a
- specimen platform for the animals and a cooled, back-thinned CCD
- camera to capture both a visible light photograph of the subjects and
- the luminescent image. Images can be obtained in less than one
- minute and are readily quantifiable.
- Siemens Inveon Micro-CT/PET
- This dual-modality system is manufactured by Siemens Medical
- Solutions (Knoxville, TN) and contains the latest in software and
- hardware. Both micro-CT and micro-PET images can be acquired,
- and image data can be co-registered so that the PET image data can
- be anatomically localized with the micro-CT imaging data.
- The micro-CT unit contains a 30-80 kVp x-ray source. The system
- allows for an approximately 9 cm x 6 cm maximum field of view.
- Ultra-high resolution images down to 15 µm of ex vivo
specimens
- can be obtained. Specialized software and phantoms for bone
- quantitation are available.
- For micro-PET studies we have ready access to 18F-FDG
for high
- resolution metabolic imaging. The instrument is capable of using CT
- or 57Co for attenuation correction. Images of one to several mm in
- spatial resolution are achievable.
CT vs X-ray ... do your users always need CT? You might also want to
think about a Faxitron, Kubtec or other X-ray machine, or Carestream
fluorescence+X-ray or the new Xenogen+X-ray.
Besides price and guesstimate of amount of use, you should also think
about service contract prices and what kind of service you are going to
afford and realistically get.
best wishes,
George
At 02:54 AM 5/7/2010, you wrote:
Hi
all,
We are in the process of setting up the first animal imaging facility in
Western Australia and in the process of purchasing an in vivo
multispectral imager and an in vivo micro CT system. We will be a running
a multi-user facility and therefore need to cater for multiple areas of
research which include animal and plant research. We are looking at
number of in vivo imaging systems including the CRiMaestro,
Calipur IVIS and the Carestream Multispectral systems. However, it is
likely that researchers will require both bioluminescence and
fluorescence capabilities which limits the Maestro system. Similarly, we
are considering a number of in vivo micro CT systems including Skyscan,
Siemens and GE-Healthcare. Versatility, reliability, sensitivity and user
friendliness are of some of the major areas of importance to us.
If any one could give us some comments, feedback or suggestions on any of
this instrumentation it would be appreciated.
Thanks
Tamara
Tamara Davey PhD
Research
Associate
Centre for Microscopy,
Characterisation and Analysis (CMCA)
The University of Western
Australia
Mail Bag
510
35 Stirling Highway, Crawley, WA
6009
Ph: +61 8 9346
4410
Email:
[hidden email]
Web:
http://www.cmca.uwa.edu.au
|
Locked
