<div dir="ltr"><div style="font-family:Aptos,Aptos_EmbeddedFont,Aptos_MSFontService,Calibri,Helvetica,sans-serif;direction:ltr;text-align:center;margin:0px;font-size:12pt;color:rgb(0,0,0)"><img src="cid:ii_m7b4kobp0" alt="Screenshot 2025-02-18 144445.jpg" style="margin-right: 0px;"><span style="font-size:small;font-family:Arial,Helvetica,sans-serif;color:rgb(34,34,34)"></span><br></div><p style="direction:ltr;text-align:center;line-height:1.2;margin-top:4.2pt;margin-right:48.8pt;margin-bottom:0px"><font face="georgia, serif" color="#073763"><span style="font-size:20pt;font-weight:700">You are cordially </span><span style="font-size:20pt;font-weight:700">invited</span><span style="font-size:20pt;font-weight:700"> to attend</span></font></p><p style="direction:ltr;text-align:center;line-height:1.2;margin-top:4.2pt;margin-right:48.8pt;margin-bottom:0px"><span style="color:black"><span class="gmail_default"><font face="georgia, serif" size="6">Julia Laskin</font></span></span></p><div style="direction:ltr;text-align:center;line-height:1.2;margin:0px 48.8pt 0px 0px"><font face="georgia, serif" color="#073763"><b><span class="gmail_default"></span><span class="gmail_default">Purdue University</span></b></font></div><div style="direction:ltr;text-align:center;line-height:1.2;margin:0px 48.8pt 0px 0px;color:rgb(23,78,134)"></div><div style="direction:ltr;text-align:center;line-height:1.2;margin:0px 48.8pt 0px 0px;font-size:12pt;color:rgb(23,78,134)"><span style="font-size:small;color:rgb(34,34,34)"></span><img src="cid:ii_m7b4kz4s1" alt="Screenshot 2025-02-14 162606.jpg" width="331" height="387"><span style="font-size:small;color:rgb(34,34,34)"></span><br></div><p style="direction:ltr;text-align:center;line-height:1.2;margin:0pt 48.8pt 0pt 0px"><font face="georgia, serif" size="4" color="#073763"><b><span class="gmail_default"></span>Ambient Mass Spectrometry Imaging: Recent Developments and Opportunities</b></font></p><p style="direction:ltr;text-align:center;line-height:1.2;margin-top:0.5pt;margin-right:48.8pt;margin-bottom:0px"><font face="georgia, serif"><span style="font-size:16pt;color:black">     </span><font size="4"><span style="color:black">  </span><span style="color:black"><b> Date:</b> Friday, <span class="gmail_default"></span>F<span class="gmail_default">ebruary 28</span></span></font></font></p><p style="direction:ltr;text-align:center;line-height:1.2;margin-top:0.5pt;margin-right:48.8pt;margin-bottom:0px"><span style="color:black"><font face="georgia, serif" size="4">     <b>Time:</b> 12pm - 1:00 pm</font></span></p><p style="direction:ltr;text-align:center;line-height:1.2;margin-top:0.5pt;margin-right:48.8pt;margin-bottom:0px"><span style="color:black"><font face="georgia, serif" size="4">  <b>    Location: </b>Genomics Auditorium 1102</font></span></p><p style="direction:ltr;text-align:center;line-height:1.2;margin-top:0.5pt;margin-right:48.8pt;margin-bottom:0px"><span style="font-size:12pt;color:black"><font face="georgia, serif"><br></font></span></p><p style="direction:ltr;text-align:center;line-height:1.2;margin-top:0px;margin-right:48.8pt;margin-bottom:0px"><span style="font-size:12pt;color:black"><b><font face="georgia, serif">Abstract:</font></b></span></p><p style="text-align:center;direction:ltr;line-height:1.2;margin-top:0px;margin-right:48.8pt;margin-bottom:0px"><font face="georgia, serif"><font size="4"><span style="color:black"><b><span class="gmail_default"></span></b></span>Mass spectrometry imaging (MSI) is a powerful technique for studying the localization of lipids, metabolites,<span class="gmail_default" style="font-size:small"> </span></font><span style="font-size:large">and proteins in biological samples. We have developed nanospray desorption electrospray ionization (nano-DESI),<span class="gmail_default" style="font-size:small"> </span></span><span style="font-size:large">an ambient ionization technique that enables label-free molecular imaging of biological samples with minimal<span class="gmail_default" style="font-size:small"> </span></span><span style="font-size:large">sample pretreatment. Nano-DESI relies on the localized liquid extraction of analyte molecules from the sample into<span class="gmail_default" style="font-size:small"> </span></span><span style="font-size:large">a liquid bridge formed between two glass capillaries. The extracted analytes are transferred to a mass spectrometer<span class="gmail_default" style="font-size:small"></span></span><span style="font-size:large">inlet and ionized by electrospray ionization. Quantification is performed by adding an internal standard to the<span class="gmail_default" style="font-size:small"> </span></span><span style="font-size:large">solvent and normalizing the signals of endogenous analytes to the<span class="gmail_default" style="font-size:small"> </span>corresponding adduct of the standard. Recent<span class="gmail_default" style="font-size:small"> </span></span><span style="font-size:large">developments of nano-DESI MSI instrumentation have enabled quantitative imaging of lipids, metabolites, and<span class="gmail_default" style="font-size:small"> </span></span><span style="font-size:large">proteins in tissues with high<span class="gmail_default" style="font-size:small"> </span>sensitivity and spatial resolution down to 8-10 microns using finely pulled capillaries.<span class="gmail_default" style="font-size:small"> </span></span><span style="font-size:large">Furthermore, we have developed a microfluidic nano-DESI probe, which greatly simplifies the<span class="gmail_default" style="font-size:small"> </span>experimental setup<span class="gmail_default" style="font-size:small"> </span></span><span style="font-size:large">and demonstrates similar performance to the capillary-based probe. We have enhanced the chemical specificity of<span class="gmail_default" style="font-size:small"> </span></span><span style="font-size:large">nano-DESI MSI experiments by coupling it with ion mobility spectrometry and online photochemical<span class="gmail_default" style="font-size:small"> </span></span><span style="font-size:large">derivatization of the extracted analytes. These complementary approaches have been used for isomer-selective<span class="gmail_default" style="font-size:small"> </span></span><font size="4">imaging of biomolecules in tissue samples. Collectively, these new spatial omics approaches will provide unique<span class="gmail_default" style="font-size:small"> </span></font><span style="font-size:large">insights into the biochemical pathways in biological systems.</span></font></p></div>