Unlock Exclusive Discounts & Flash Sales! Click Here to Join the Deals on Every Wednesday!

Simultaneous detection of phosphatidylcholines and glycerolipids by matrix-enhanced surface-assisted laser desorption/ionization-mass spectrometry (CAT#: STEM-ST-0355-LJX)

Introduction

Matrix-assisted laser desorption/ionisation (MALDI) imaging mass spectrometry (IMS) allows for the simultaneous detection and imaging of several molecules in brain tissue. However, the detection of glycerolipids such as diacylglycerol (DAG) and triacylglycerol (TAG) in brain tissues is hindered in MALDI-IMS because of the ion suppression effect from excessive ion yields of phosphatidylcholine (PC). In this study, we describe an approach that employs a homogeneously deposited metal nanoparticle layer (or film) for the detection of glycerolipids in rat brain tissue sections using IMS. Surface-assisted laser desorption/ionisation IMS with sputter-deposited Pt film (Pt-SALDI-IMS) for lipid analysis was performed as a solvent-free and organic matrix-free method. Pt-SALDI produced a homogenous layer of nanoparticles over the surface of the rat brain tissue section. Highly selective detection of lipids was possible by MALDI-IMS and Pt-SALDI-IMS; MALDI-IMS detected the dominant ion peak of PC in the tissue section, and there were no ion peaks representing glycerolipids such as DAG and TAG. In contrast, Pt-SALDI-IMS allowed the detection of these glycerolipids, but not PC. Therefore, using a hybrid method combining MALDI and Pt-SALDI (i.e., matrix-enhanced [ME]-Pt-SALDI-IMS), we achieved the simultaneous detection of PC, PE and DAG in rat brain tissue sections, and the sensitivity for the detection of these molecules was better than that of MALDI-IMS or Pt-SALDI alone. The present simple ME-Pt-SALDI approach for the simultaneous detection of PC and DAG using two matrices (sputter-deposited Pt film and DHB matrix) would be useful in imaging analyses of biological tissue sections.




Principle

The surface enhanced laser desorption ionization technique belongs to laser desorption mass spectrometry (LDMS). It is different from ordinary LDMS in that the laser is not directly hit on the sample to desorption, but the sample is suspended in the matrix, the laser is hit on the matrix, the matrix absorbs and transmits the laser energy, so that the sample in the matrix desorption out. After desorption and ionization, the samples were examined in a time-flight mass spectrometer.

Applications

For protein analysis and measurement of molecular weight of complete proteins
For the diagnosis of a variety of diseases, especially cancer

Procedure

1. The surface of the protein chip is treated in a certain chemical or biochemical way (surface enhancement), so that it has the ability to bind specifically to a certain type of protein
2. The serum or protein extract is directly added to the surface of the chip, and the chip is washed after incubation. Specific proteins bind to the chip and are thus separated from the protein mixture
3. The chip then uses a "chip reader" (a kind of SELDI-TOF-MS) to obtain a mass spectrum of the protein bound to the chip
4. The SELDI protein chip system can be used to compare changes in the protein profile of any set of control samples or different disease states to identify biomarkers or disease-related targets

Materials

• Sample Type:
Rat brain tissue section

Notes

When operating, strictly follow the experimental steps.
Advertisement