We gratefully acknowledge startup funds from Wayne State University (MJA), a grant from the American Foundation for Aging Research (SMV), and a Pathway to Independence Career Transition Award (R00EB007129) from the National Institute of Biomedical Imaging and Bioengineering of the National Institutes of Health (MJA).

1. Metalation using LnCl3 salts
<ol>
	<li>Dissolve the ligand in water to produce a solution of 30-265 mM. The ligand 2-(4-isothiocyanatobenzyl)-diethylenetriamine pentaacetic acid 
	(p-SCN-Bn-DTPA) was used in this video at a concentration of 73 mM.</li>
	<li>Adjust the pH of the solution of ligand to between 5.5 and 7.0 by adding 1 M NH4OH. In this video, 0.2 mL of the 1 M NH4OH solution was used.</li>
	<li>Dissolve 1-2 equivalents of LnCl3 in water to produce a so...

<ol>
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Given the increasing number of publications that include lanthanide-based contrast agents4-14, it is important that care is taken in preparing, purifying, and characterizing products to ensure reproducible and comparable results. These complexes are often considered challenging to purify and characterize relative to organic molecules due to their paramagnetic nature and the sensitivity 
of any functional groups that could be used for bioconjugation. We have described common methods for the synthesis, purificat...

<table border="1">
 <tbody>
 <tr>
 <th>Reagents and Equipment</th>
 <th>Company</th>
 <th>Catalogue number</th>
 </tr>
 <tr>
 <td>EuCl3&bull;6H2O</td>
 <td>Sigma-Aldrich</td>
 <td>203254-5G</td>
 </tr>
 <tr>
 <td>p-SCN-Bn-DTPA</td>
 <td>Macrocyclics</td>
 <td>B-305</td>
 </tr>
 <tr>
 <td>ammonium hydroxide</td>
 <td>EMD</td>
 <td>AX1303-3</td>
 </tr>
 <tr>
 <td>Spectra/Por Biotech Cellulose Ester (CE) Dialysis Membrane - 500 D MWCO</td>
 <td>Fisher Scientific</td>
 <td>68-671-24</td>
 </tr>
 <tr>
 <td>Millipore IC Millex-LG Filter Units</td>
 <td>Fisher Scientific</td>
 <td>SLLG C13 NL</td>
 </tr>
 <tr>
 <td>xylenol orange tetrasodium salt</td>
 <td>Alfa Aesar</td>
 <td>41379</td>
 </tr>
 <tr>
 <td>acetic acid</td>
 <td>Fluka</td>
 <td>49199</td>
 </tr>
 <tr>
 <td>D2O</td>
 <td>Cambridge Isotope Laboratories, Inc.</td>
 <td>DLM-4-25</td>
 </tr>
 <tr>
 <td>water purifier</td>
 <td>ELGA</td>
 <td>Purelab Ultra</td>
 </tr>
 <tr>
 <td>high performance liquid chromatography and mass spectrometry</td>
 <td>Shimadzu</td>
 <td>LCMS-2010EV</td>
 </tr>
 <tr>
 <td>relaxation time analyzer</td>
 <td>Bruker</td>
 <td>mq60 minispec</td>
 </tr>
 <tr>
 <td>UV-vis spectrophotometer</td>
 <td>Fisher Scientific</td>
 <td>20-624-00092</td>
 </tr>
 <tr>
 <td>freeze dryer</td>
 <td>Fisher Scientific</td>
 <td>10-030-133</td>
 </tr>
 <tr>
 <td>pH meter</td>
 <td>Hanna Instruments</td>
 <td>HI 221</td>
 </tr>
 <tr>
 <td>spectrofluorometer</td>
 <td>HORIBA Jobin Yvon</td>
 <td>Fluoromax-4</td>
 </tr>
 <tr>
 <td>Molecular Weight Calculator version 6.46 by Matthew Monroe, downloaded October 17, 2009</td>
 <td><a href="http://ncrr.pnl.gov/software/">http://ncrr.pnl.gov/software/</a></td>
 <td>Molecular Weight Calculator</td>
 </tr>
 </tbody>
</table>

preparation, purification, and characterization of lanthanide complexes for use as contrast agents for magnetic resonance imaging

Polyaminopolycarboxylate-based ligands are commonly used to chelate lanthanide ions, and the resulting complexes are 
useful as contrast agents for magnetic resonance imaging (MRI). Many commercially available ligands are especially useful because they contain 
functional groups that allow for fast, high-purity, and high-yielding conjugation to macromolecules and biomolecules via amine-reactive 
activated esters and isothiocyanate groups or thiol-reactive maleimides. While metalation of these ligands is considered common 
knowledge in the field of bioconjugation chemistry, subtle differences in metalation procedures must be taken into account when 
selecting metal starting materials. Furthermore, multiple options for purification and characterization exist, and selection of the most 
effective procedure partially depends on the selection of starting materials. These subtle differences are often neglected in published 
protocols. Here, our goal is to demonstrate common methods for metalation, purification, and characterization of lanthanide complexes 
that can be used as contrast agents for MRI (Figure 1). We expect that this publication will enable biomedical scientists to incorporate 
lanthanide complexation reactions into their repertoire of commonly used reactions by easing the selection of starting materials and 
purification methods.

Watch this Scientific Journal Video about Preparation, Purification, and Characterization of Lanthanide Complexes for Use as Contrast Agents for Magnetic Resonance Imaging at JoVE.com

Preparation, Purification, and Characterization of Lanthanide Complexes for Use as Contrast Agents for Magnetic Resonance Imaging

We demonstrate the metalation, purification, and characterization of lanthanide complexes. The complexes described here can be conjugated to macromolecules to enable tracking of these molecules using magnetic resonance imaging.

Polyaminopolycarboxylate-based ligands are commonly used to chelate lanthanide ions, and the resulting complexes are 
useful as contrast agents for ...

preparation-purification-characterization-lanthanide-complexes-for

Research

JoVE Journal

Biology

14.9K Views.  Wayne State University. Dimostriamo la metalation, purificazione e caratterizzazione di complessi di lantanidi. I complessi qui descritto può essere coniugato con macromolecole di attivare il rilevamento di queste molecole usando la risonanza magnetica.