Non-Radioactive Microspheres 
                                              Regional Blood Flow Determination

DyeTrak Microsphere brochure  (pdf)
Microsphere Bibliography
(Web view )
Microsphere Bibliography  (printable pdf )

Radioactive microspheres have been used for many years as the standard for measuring regional blood flow
 distribution in animal research models.  Radioactive microspheres have many negative health, safety and
 environmental issues associated with their use.

Triton Technology offers a variety of non-radioactive tracer microspheres for determination of regional blood
 flow distribution and particle deposition .  Monodisperse tracer microspheres are made of  stable polystyrene
 latex cross-linked with 2% DVB.  These microspheres are marked with one of several unique families of markers
 and used to measure regional blood flow at different time points during the course of an experiment.  Typically
 blood flow measurements are made using 15um diameter microspheres. Occasionally 10um microspheres are
 also used for blood flow applications.

Dye-Trak®   colored microspheres are a safe new non-radioactive method of measuring regional
 blood flow in experimental preparations. Polystyrene microspheres of highly uniform diameter are precision
 dyed with one a number of possible colors (5 to 7). Original Dye-Trak® offers five colors and the newer
 Dye-Trak® VII+ offers seven colors. Using an injection of  Dye-Trak® spheres into a local end-organ perfusion
 line or the  left atrium, regional blood flow can be determined. The spheres are recovered from tissue and blood
 samples by digestion and subsequent centrifugation or micro-filtration. The dyes are then eluted from the
 recovered microspheres with a known volume of a solvent and the dye concentrations are determined by
  spectrophotometry. The separation of a  composite absorbance spectrum using the Dye-Trak® method is as
 accurate as the separation of energy spectra using the radioactive microsphere technique.  Dye-Trak®
 measurement of regional blood flow yields the same values as with radioactive microspheres, without the
 difficulties associated with radioactivity.  Dye-Trak® is available in two variations: the original 5-color palette
 and a recently developed Dye-Trak® VII+  7-color palette.  The recommended colors to use for a given number
 of injections is listed in a Color Progression Table.   While the original dye-Trak colors are still available we are
 recommending that new users use Dye-Trak VII+ for their experiments.  

microspheres are defined by Triton Technology US patents  5,230,343 and 5,253,649 and foreign.

Dye-Trak®'F'  fluorescent microspheres offer high sensitivity measurement of
 regional blood flow determination quantified by fluorescence spectroscopy.   Using an injection of 
 fluorescent microspheres  into a local end-organ perfusion line or the left atrium, regional blood flow can be
 determined. The spheres are recovered from tissue and blood samples by digestion and subsequent
 centrifugation or micro-filtration. The dyes are then eluted from the recovered microspheres with a known
 volume of a solvent and the dye concentrations determined by fluorescence spectrophotometry. The separation
 of a composite emission spectrum using the fluorescent microsphere method is as accurate as the separation of
 energy spectra using the radioactive microsphere technique.  This method offers greater sensitivity for low flow
 situations and there are a large number of  markers available.   

® 'F'
microspheres are defined by Triton Technology 
 US patents 5,230,343,  5,253,649 and foreign.



BioPAL    Neutron-Activated Microspheres
The BioPAL neutron activated microspheres were patented by W Scott Kemper of Triton Technology and Christopher Rheinhardt of Biopal (US patent 6,328,700).   For information on BioPAL microspheres, contact Triton Technology:     619-665-7199



Copyright 1995-2000 Triton Technology, Inc.

Updated Dec12, 2015

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