Sample preparation protocol

Figure 8.2 Sample preparation protocols, currently employed in malaria parasite detection by LDMS. Both protocols require less than 50pl blood, obtained by either finger-stick or phlebotomy.

In the first LDMS-based detection of malaria in human subjects (unpublished), lOOpl P. falciparum or P. v/vax-infected blood samples, grouped into three different parasitemia ranges—low (10-150 parasites/pl), mid (2 x 103 parasites/pl), and high (25 x 103-60 x 103 parasites/pl)—have been examined using both sample preparation protocols. Parasitemia levels in these samples were previously determined independently for each sample by optical microscopy examination of blood smears. The LDMS data clearly indicate that... 

In real life, sample preparation techniques are utilized in tandem with HPLC/MS/MS. Due to the high selectivity of LC/MS/MS in the SRM mode, small quantities of impurities or interferences in the purified fractions from sample preparation protocols dealing with biological matrices can be tolerated. This is especially true for protein precipitation, which is widely used because of simplicity and rapidity, when high-throughput turn-around is required. High-throughput HPLC is discussed elsewhere in this book. 

E. Nordhoff, M. Schurenberg, G. Thiele, C. Lubbert, K.-D. Kloeppel, D. Theiss, H. Lehrach, and J. Gobom. Sample Preparation Protocols for MALDI-MS of Peptides and Oligonucleotides Using Prestructured Sample Supports. Int. J. Mass Spectrom., 226(2003) 163-180. 

The methods to be used and a copy of Standard Operating Procedures (SOPs) where accredited, including any sampling and sample preparation protocols, to be supplied to the customer. 

P5 Effect of Sample Preparation Protocol. Our preliminary studies... 

The panel meeting was organized and conducted to facilitate development of sample preparation protocols for mutagenicity testing of six media air, drinking water, nonaqueous liquid wastes, soils and sediments, waste solids, and waste water. The meeting objectives were established by the sponsors and were as follows ... 

Evaluate the adequacy and validity of the selected and reviewed sample preparation protocol for each medium. 

Prepare revised sample preparation protocols in accordance with review comments and recommendations from the panel meeting participants. 

Recommend additional research to support further development of medium-specific sample preparation protocols. 

Like infrared spectroscopy, specific test methods for recording the nuclear magnetic resonance spectroscopy of coal do not exist. It is necessary, therefore, to adapt other methods to the task at hand, provided that the necessary sample preparation protocols and instrumental protocols for recording magnetic resonance spectra are followed to the letter as proposed and described for infrared spectroscopy (Section 9.1). 

We have carried out an extensive literature search on sample preparation technologies and found many papers on conventional chromatography and capillary electrophoresis methods but few on NLC and NCE. It is important to mention here that sample preparation methodologies used in conventional chromatography and capillary electrophoresis can be used in NLC and NCE. The interested reader can consult our earlier books for details [20,21], However, attempts have been made to describe sample preparation protocols required in NLC and NCE techniques. Some of the important requirements and preparations are discussed below. 

The matrix selection and deposition for MALDI-IMS is another crucial step in the sample preparation protocol. The matrix, solvent, concentration of matrix, and the protocol of coating matrix have to be optimized first and then used for the real samples detection. 

The enzymes mentioned above have been compared several times in an attempt to elaborate a generally applicable sample preparation protocol. Moreno et al. [89] compared pronase E and subtilisin in the case of oyster and mussel samples. They resorted to phosphate buffer during proteolysis, which resulted in a... 

Matrix selection and optimization of the sample preparation protocol are the most important steps in the analysis because the quality of the results depends on good sample preparation. However, the preparation procedures are still empirical. The MALDI matrix selection is based on the laser wavelength used. In addition, the most effective matrix is strongly related to the class of analyte and may differ for analytes that have apparently similar structures. The MALDI matrices must meet a number of requirements simultaneously. These are strong absorbance at the laser wavelength, low enough mass to be sublimable,... 

Figure 13-12. Representative MRM scans obtained using the ion-suppression infusion experiment, developed by King and co-workers [35]. A significant ion matrix effect is observed between 0.5 and Imin using control rat plasma. The sample preparation was PPT. Note that this experiment needs to be performed prior to the method development and validation, so necessary changes to the sample preparation protocol and chromatographic method are made. Reprinted with permission from [101].

The same concept in proteomics studies has technological implications, e.g., which method, sample preparation protocols, and instrumentation will be used. Again, top-down analysis will be based on isolation, analysis, and characterization of an intact protein to reveal its function. Fourier transformed ion cyclotron resonance mass spectrometry (FT-ICR) (Marshall et al., 1998) facilitates such approach in protein identification as a result of random fragmentation of an intact molecule. In contrary, bottom-up approach is based on up-front fragmentation of the protein in question using various proteolytic enzymes with known specificity (Chalmers et al., 2005 Millea et al., 2006). In these experiments, trypsin is most commonly used. An important question that remains is whether more... 

The standard methods that one would use in sample preparation for chromatography include filtration, sedimentation, centrifugation, liquid-liquid extraction (LEE) open-column chromatography, and concentration/evaporation. Filtration for sample preparation may be performed on numerous occasions in a sample preparation protocol, with the first filtration being used to separate large-particulate matter from solvent. 

Two additional techniques that are used in sample preparation protocols are ultrafiltration and microdialysis. In ultrafiltration, pressure is applied to a membrane and those molecules smaller than the mo-... 

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