Oligonucleotide Mass Analysis and In-source Decay Sequencing on a MALDI TOF Mass Spectrometer

User Benefits

- Accurate mass analysis of oligonucleotides using linear or reflectron mode - Rapid, simple sequence determination by ISD requiring no new sample preparation - Unattended operation through automation of both mass analysis and ISD procedures

Introduction

Mass spectrometry has the capacity to analyze oligonucleotides more quickly and accurately than many other techniques. These important factors become critical in a high throughput environment, for example in the case of industrial primer synthesis where tens of thousands of samples may be generated each day. Here, it is vital that the product quality is of a high standard and that the correct sequence has been generated. Limitations arise when the nature of the sample is considered. For example, electrospray experiments may be difficult due to the high salt content of synthesised primers that can suppress the ionization process, produce cationic salt adducts, and promote multiple charge states making spectral interpretation more complicated. It has been previously demonstrated that MALDI TOF mass spectrometry can efficiently analyze large numbers of samples under fully automated conditions with accuracy sufficient to identify a primer by its expected intact mass. This methodology is not labour intensive and requires little or no sample clean-up prior to analysis. The resultant spectrum is usually uncomplicated and easy to interpret. This process has subsequently been accepted by numerous enterprises as an industry standard method of quality control. Following on from these simple mass identification experiments, we have progressed to oligonucleotide sequencing using MALDI mass spectrometry. It has been well documented that this type of sample may be sequenced using sophisticated DNA sequencers or by enzymatic digestion followed by mass spectrometry. Here we will present a simple and speedy method of sequencing oligonucleotides that requires no further sample preparation and little expertise.

December 6, 2013 GMT