DNA SEQUENCE LADDER READOUT BY MASS SPECTROMETRY

提出了一种用于快速读出的新的质谱学方法 桑格双脱氧DNA序列梯形图。离子将会产生 使用一种相对较新的技术，称为海量集群 影响(MCI)解吸。MCI从以下物质中产生气相离子 固体或液体(溶液)被超高速撞击的目标 大量、高电荷量的甘油或水除尘器 通过电喷雾过程进行真空。超高速星系团 撞击已经被证明是冲击-加热和解吸大量的生物分子离子 具有低程度的内部激发，因此长时间 寿命，允许质量良好的质谱学检测 决议。离子是在真空中产生的，因此可以进行有效的运输 进入质谱仪，并最大限度地减少样品大小的要求。这个 解吸离子的多重带电初始程度相对较低 很低。为了完成这些研究，团簇离子源和样品 引入系统将连接到飞行时间质量 脉冲正交离子引出An离子光谱仪 高质量分辨率的反射器。方法来控制 将对收费程度进行调查：其中包括 团簇电荷和能量，以及掺杂靶材和/或 带有质子供体或受体的团簇进料液扰动 DNA分析物对带电溶液物种的竞争 或由于撞击而带进表面的多余质子 集群。灵活的充电控制，最大限度地减少多次充电 应允许对多组分DNA序列进行优化分析 梯形混合液。调查集群的竞争角色 分析离子测定中的电荷和电离平衡 电荷的多重性，也将在其中进行实验 含有分析物的簇合物通过电喷雾和脱溶 对清洁的固体和液体目标的影响。DNA的MCI解吸 将对亲和捕获表面进行研究，以便 促进样品清理并将样品大小要求降至最低。

A new mass spectrometric approach is proposed for rapid readout of Sanger dideoxy DNA sequence ladders. Ions will be generated using the relatively new technique known as Massive Cluster Impact (MCI) desorption. MCI generates vapor-phase ions from solid or liquid (solution) targets by the hypervelocity impact of massive, highly-charged glycerol or water dusters produced in vacuum by an electrospray process. The hypervelocity cluster impact has been shown to shock-heat and desorb massive biomolecular ions with a low degree of internal excitation and consequently long lifetimes, allowing mass spectrometric detection with good mass resolution. Ions arc generated in vacuum, allowing efficient transport into the mass spectrometer and minimizing sample size requirements. The initial extent of multiple charging in the desorbed ions is relatively low. To accomplish these studies, a cluster ion source and sample introduction system will be interfaced to a time-of-flight mass spectrometer with pulsed orthogonal ion extraction and an ion reflector for high mass resolution. Methods to control the degree of charging will be investigated: these include varying the cluster charge and energy, and doping the target and/or the cluster feed liquid with proton donors or acceptors to perturb the competition of the DNA analyte for charged solution species or the excess protons carried into the surface by the impacting cluster. Facile charge control which minimizes multiple charging should allow optimized analyses of multicomponent DNA sequence ladder mixtures. To investigate the competing roles of cluster charge and ionization equilibria in determining analyte ion charge multiplicity, experiments will also be performed in which analyte-containing clusters are electrosprayed and desolvated by impact on clean solid and liquid targets. MCI desorption of DNA from affinity capture surfaces will be investigated, in order to facilitate sample cleanup and minimize sample size requirements.