Name: preparation of homogeneous maldi samples for quantitative applications
Uploaded: 2016-10-28T13:00:00
Description: Watch this Scientific Journal Video about Preparation of Homogeneous MALDI Samples for Quantitative Applications at JoVE.com

This work is supported by the Genomics Research Center, Academia Sinica and the Ministry of Science and Technology of Taiwan, the Republic of China (Contract No. 104-2119-M-001-014).

NOTA: Este protocolo é desenvolvido para reduzir a heterogeneidade espacial do fragmento maltotriose e bradicinina (1-7) preparado com o método da gota seco. O protocolo consiste em três etapas principais, incluindo a preparação e pré-condicionamento, a deposição de amostra e de secagem e análise de dados de espectrometria de massa. Os procedimentos são descritos e descritos com mais detalhe a seguir: 1. Preparação e pré-condicionamento <ol><li> Limpeza da placa de amostra <ol><li> Usar luvas de b...

<ol>
	<li>Karas, M., Hillenkamp, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Laser+Desorption+Ionization+of+Proteins+with+Molecular+Masses+Exceeding+10000+Daltons.">Laser Desorption Ionization of Proteins with Molecular Masses Exceeding 10000 Daltons.</a> Anal. Chem. 60, 2299-2301 (1988).</li><li>Beavis, R. C., Chait, B. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Velocity+Distributions+of+Intact+High+Mass+Polypeptide+Molecule+Ions+Produced+by+Matrix+Assisted+Laser+Desorption.">Velocity Distributions of Intact High Mass Polypeptide Molecule Ions Produced by Matrix Assisted Laser Desorption.</a> Chem. Phys. Lett. 181, 479-484 (1991).</li><li>Beavis, R. C., Chaudhary, T., Chait, B. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Alpha-Cyano-4-Hydroxycinnamic+Acid+as+a+Matrix+for+Matrix-Assisted+Laser+Desorption+Mass-Spectrometry.">Alpha-Cyano-4-Hydroxycinnamic Acid as a Matrix for Matrix-Assisted Laser Desorption Mass-Spectrometry.</a> Org. Mass Spectrom. 27, 156-158 (1992).</li><li>Ehring, H., Karas, M., Hillenkamp, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Role+of+Photoionization+and+Photochemistry+in+Ionization+Processes+of+Organic-Molecules+and+Relevance+for+Matrix-Assisted+Laser+Desorption+Ionization+Mass-Spectrometry.">Role of Photoionization and Photochemistry in Ionization Processes of Organic-Molecules and Relevance for Matrix-Assisted Laser Desorption Ionization Mass-Spectrometry.</a> Org. Mass Spectrom. 27, 472-480 (1992).</li><li>Strupat, K., Karas, M., Hillenkamp, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=2,5-Dihydroxybenzoic+Acid+-+a+New+Matrix+for+Laser+Desorption+Ionization+Mass-Spectrometry.">2,5-Dihydroxybenzoic Acid - a New Matrix for Laser Desorption Ionization Mass-Spectrometry.</a> Int. J. Mass Spectrom. Ion Process. 111, 89-102 (1991).</li><li>Hu, H., Larson, R. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Evaporation+of+a+Sessile+Droplet+on+a+Substrate.">Evaporation of a Sessile Droplet on a Substrate.</a> J. Phys. Chem. B. 106, 1334-1344 (2002).</li><li>Deegan, R. D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Capillary+Flow+as+the+Cause+of+Ring+Stains+from+Dried+Liquid+Drops.">Capillary Flow as the Cause of Ring Stains from Dried Liquid Drops.</a> Nature. 389, 827-829 (1997).</li><li>Hu, J. -. B., Chen, Y. -. C., Urban, P. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Coffee-Ring+Effects+in+Laser+Desorption/Ionization+Mass+Spectrometry.">Coffee-Ring Effects in Laser Desorption/Ionization Mass Spectrometry.</a> Anal. Chim. Acta. 766, 77-82 (2013).</li><li>Schwartz, S. A., Reyzer, M. L., Caprioli, R. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Direct+Tissue+Analysis+Using+Matrix-Assisted+Laser+Desorption/Ionization+Mass+Spectrometry:+Practical+Aspects+of+Sample+Preparation.">Direct Tissue Analysis Using Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry: Practical Aspects of Sample Preparation.</a> J. Mass Spectrom. 38, 699-708 (2003).</li><li>Hu, H., Larson, R. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Marangoni+Effect+Reverses+Coffee-Ring+Depositions.">Marangoni Effect Reverses Coffee-Ring Depositions.</a> J. Phys. Chem. B. 110, 7090-7094 (2006).</li><li>Bhardwaj, R., Fang, X., Attinger, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pattern+Formation+During+the+Evaporation+of+a+Colloidal+Nanoliter+Drop:+A+Numerical+and+Experimental+Study.">Pattern Formation During the Evaporation of a Colloidal Nanoliter Drop: A Numerical and Experimental Study.</a> New J. Phys. 11, 075020 (2009).</li><li>Savino, R., Paterna, D., Favaloro, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Buoyancy+and+Marangoni+Effects+in+an+Evaporating+Drop.">Buoyancy and Marangoni Effects in an Evaporating Drop.</a> J Thermophys Heat Tr. 16, 562-574 (2002).</li><li>Probstein, R. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Surface Tension. in Physicochemical Hydrodynamics : An Introduction. , 305-361 (1994).</li><li>Lai, Y. -. H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Reducing+Spatial+Heterogeneity+of+MALDI+Samples+with+Marangoni+Flows+During+Sample+Preparation.">Reducing Spatial Heterogeneity of MALDI Samples with Marangoni Flows During Sample Preparation.</a> J. Am. Soc. Mass Spectrom. 27, 1314-1321 (2016).</li><li>Hsiao, C. -. H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comprehensive+Molecular+Imaging+of+Photolabile+Surface+Samples+with+Synchronized+Dual-Polarity+Time-of-Flight+Mass+Spectrometry.">Comprehensive Molecular Imaging of Photolabile Surface Samples with Synchronized Dual-Polarity Time-of-Flight Mass Spectrometry.</a> Rapid Commun. Mass Spectrom. 25, 834-842 (2011).</li><li>Vorm, O., Roepstorff, P., Mann, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Improved+Resolution+and+Very+High-Sensitivity+in+MALDI+TOF+of+Matrix+Surfaces+Made+by+Fast+Evaporation.">Improved Resolution and Very High-Sensitivity in MALDI TOF of Matrix Surfaces Made by Fast Evaporation.</a> Anal. Chem. 66, 3281-3287 (1994).</li><li>Gabriel, S. J., Schwarzinger, C., Schwarzinger, B., Panne, U., Weidner, S. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Matrix+Segregation+as+the+Major+Cause+for+Sample+Inhomogeneity+in+MALDI+Dried+Droplet+Spots.">Matrix Segregation as the Major Cause for Sample Inhomogeneity in MALDI Dried Droplet Spots.</a> J. Am. Soc. Mass Spectrom. 25, 1356-1363 (2014).</li><li>Mampallil, D., Eral, H. B., van den Ende, D., Mugele, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Control+of+Evaporating+Complex+Fluids+through+Electrowetting.">Control of Evaporating Complex Fluids through Electrowetting.</a> Soft Matter. 8, 10614-10617 (2012).</li></ol>

Com base em previsões teóricas anteriores, fluxos hidrodinâmicos induzidas pela temperatura dentro de gotículas pode ultrapassar para fora fluxos capilares induzidas por evaporação do solvente. A eficiência de tais moléculas de recirculação interna é aumentada quando a gradientes de temperatura dentro de um aumento de gotícula. De acordo com os resultados previstos, ao manter a temperatura da placa de amostra abaixo de 5 ° C, mantendo a sua envolvente, à temperatura ambiente, a velocidade média de fluxo d...

Mass spectrometry (MS) is one of the most important analytical techniques for analyzing the molecular compositions of complex samples. Among all the ionization methods used in MS, matrix-assisted laser desorption/ionization (MALDI) is the most sensitive and widely used method in bioanalytical applications.1 In comparison to other ionization techniques, MALDI has the highest sensitivity and high tolerance to salt contaminants. Such analytical properties make MALDI the first choice for carbohydrate analysis and many proteomics applications. However, sample preparation is a crucial step for obtaining high quality data in MALDI-MS.
The most commonly used sample preparation method for MALDI-MS is the dried-droplet method, in which sample droplets are deposited on a surface and dried under ambient conditions. This drying method is simple and generally effective.2-5 However, a common problem in the dried-droplet method is that the resultant analyte/matrix crystals normally distribute irregularly. In many cases, the crystals aggregate at the periphery of sample areas, resulting in the so-called ring-stain formation.6-8 The heterogeneous crystal morphologies affect the spatial distribution of analyte molecules, which results in severe fluctuation in ion signal over sample areas. Such severe signal fluctuations and poor data reproducibility are known as the "sweet spot" problem in MALDI-MS.9 Thus, there is a great need for reducing spatial heterogeneities in MALDI-MS dried droplet applications.
Hydrodynamic flows in the sample droplet play an important role in determining the spatial distribution of samples prepared with the dried-droplet method.10-12 It was found that the evaporation of solvent induces outward capillary flows within droplets, which are responsible for the ring-stain formation.7,10 In contrast, recirculation flows induced by tangential surface-tension gradients may counterbalance the outward capillary flows.13 If the recirculation flow speeds are higher than that of the outward capillary flows, the samples can be efficiently redistributed to reduce the heterogeneity problem.14
In this work, we demonstrate a detailed protocol for preparing samples with a simple drying chamber to induce efficient recirculation flows during droplet drying processes. Droplet drying conditions are precisely controlled, including the temperatures of the sample plate and its surroundings, and the relative humidity within the chamber. The model analytes include maltotriose and bradykinin chain (1-7). The matrix used for the demonstration is 2,4,6-trihydroxyacetophenone (THAP). The samples are examined with time-of-flight (TOF) MS, and the data are analyzed quantitatively to show the reduction of heterogeneity.

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			<td height="21" style="height:21px;width:303px;">Name of Reagent</td>
			<td style="width:157px;"></td>
			<td style="width:139px;"></td>
			<td style="width:191px;"></td>
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		<tr height="21">
			<td height="21" style="height:21px;width:303px;">Detergent powder</td>
			<td style="width:157px;">Alconox</td>
			<td style="width:139px;">242985</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:303px;">Methanol</td>
			<td style="width:157px;">Merck</td>
			<td style="width:139px;">106009</td>
			<td></td>
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		<tr height="21">
			<td height="21" style="height:21px;width:303px;">Acetonitrile</td>
			<td style="width:157px;">Merck</td>
			<td style="width:139px;">100003</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:303px;">2,4,6-trihydroxyacetophenone (THAP)</td>
			<td style="width:157px;">Sigma-Aldrich</td>
			<td style="width:139px;">T64602&#160;</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:303px;">Bradykinin fragment (1-7)</td>
			<td style="width:157px;">Sigma-Aldrich</td>
			<td style="width:139px;">B1651</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:303px;">Maltotriose</td>
			<td style="width:157px;">Sigma-Aldrich</td>
			<td style="width:139px;">47884</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:303px;">Pipette tips</td>
			<td style="width:157px;">Mettler Toledo</td>
			<td style="width:139px;">17005091</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:303px;">Microcentrifuge tube</td>
			<td style="width:157px;">Axygen</td>
			<td style="width:139px;">MCT-150-C</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:303px;"></td>
			<td style="width:157px;"></td>
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		<tr height="21">
			<td height="21" style="height:21px;width:303px;">Name of Equipment</td>
			<td style="width:157px;"></td>
			<td style="width:139px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:303px;">Milli-Q water purification system</td>
			<td style="width:157px;">Millipore</td>
			<td style="width:139px;">ZMQS6VFT1</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Powder-free nitrile gloves</td>
			<td style="width:157px;">Microflex</td>
			<td style="width:139px;">SU-690</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:303px;">600 mL beaker</td>
			<td style="width:157px;">Duran</td>
			<td style="width:139px;">2110648</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:303px;">Ultrasonic cleaner</td>
			<td style="width:157px;">Delta</td>
			<td style="width:139px;">DC300H</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:303px;">Hygrometer</td>
			<td style="width:157px;">Wisewind</td>
			<td style="width:139px;">5330</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:303px;">Nitrogen gas flowmeter</td>
			<td style="width:157px;">Dwyer</td>
			<td style="width:139px;">RMA-6-SSV</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:303px;">K-type thermocouples</td>
			<td style="width:157px;">Digitron</td>
			<td style="width:139px;">311-1670</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:303px;">Centrifuge</td>
			<td style="width:157px;">Select BioProducts</td>
			<td style="width:139px;">Force Mini&#160;</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:303px;">Pipette</td>
			<td style="width:157px;">Rainin</td>
			<td style="width:139px;">pipet-lite XLS</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:303px;">Stereomicroscope</td>
			<td style="width:157px;">Olympus</td>
			<td style="width:139px;">SZX16</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:303px;">Temperature controllable drying chamber</td>
			<td style="width:157px;">this lab</td>
			<td style="width:139px;"></td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:303px;">Synchronized dual-polarity time-of-flight imaging mass spectrometer (DP-TOF IMS)</td>
			<td style="width:157px;">this lab</td>
			<td style="width:139px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:303px;">MALDI-TOF stainless steel sample target</td>
			<td style="width:157px;">this lab</td>
			<td style="width:139px;"></td>
			<td></td>
		</tr>
	</tbody>
</table>

preparation of homogeneous maldi samples for quantitative applications

This protocol demonstrates a simple sample preparation to reduce spatial heterogeneity in ion signals during matrix-assisted laser desorption/ionization (MALDI) mass spectrometry. The heterogeneity of ion signals is a severe problem in MALDI, which results in poor data reproducibility and makes MALDI unsuitable for quantitative analysis. By regulating sample plate temperature during sample preparation, thermal-induced hydrodynamic flows inside droplets of sample solution are able to reduce the heterogeneity problem. A room-temperature sample preparation chamber equipped with a temperature-regulated copper base block that holds MALDI sample plates facilitates precise control of the sample drying condition. After drying of sample droplets, the temperature of sample plates is returned to room temperature and removed from the chamber for subsequent mass spectrometric analysis. The areas of samples are examined with MALDI-imaging mass spectrometry to obtain the spatial distribution of all components in the sample. In comparison with the conventional dried-droplet method that prepares samples under ambient conditions without temperature control, the samples prepared with the method demonstrated herein show significantly better spatial distribution and signal intensity. According to observations using carbohydrate and peptide samples, decreasing substrate temperature while maintaining the surroundings at ambient temperature during the drying process can effectively reduce the heterogeneity of ion signals. This method is generally applicable to various combinations of samples and matrices.

As imagens de campo brilhante, bem como as imagens de MS fragmento maltotriose e bradicinina (1-7) preparado, com a temperatura da placa de amostra de 5 e 25 ° C são apresentados na Figura 1. No caso de maltotriose sodiated, o sinal de iões principalmente povoa na periferia da área de amostra quando é preparado com uma temperatura de placa de amostra de 25 ° C. Diminuindo a temperatura da placa de amostra a 5 ° C, o sinal preenche de forma homogénea sobre toda a ...

Watch this Scientific Journal Video about Preparation of Homogeneous MALDI Samples for Quantitative Applications at JoVE.com

Preparation of Homogeneous MALDI Samples for Quantitative Applications

Um protocolo para reduzir as heterogeneidades espaciais dos sinais de iões em espectrometria de massa MALDI por regulação da temperatura do substrato durante o processo de secagem da amostra é demonstrada.

Preparação de Amostras de MALDI homogênea para Aplicações quantitativas

This protocol demonstrates a simple sample preparation to reduce spatial heterogeneity in ion signals during matrix-assisted laser desorption/ionization ...

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