Wu K J, Steding A, Becker C H
Molecular Physics Laboratory, SRI International, Menlo Park, CA 94025.
Rapid Commun Mass Spectrom. 1993 Feb;7(2):142-6. doi: 10.1002/rcm.1290070206.
Matrix-assisted laser desorption time-of-flight mass spectrometry has been used to produce quasi-molecular ion signals from underivatized mixed-base single-stranded DNA oligomers ranging from 10 to 67 nucleotides in length. These results were obtained with a new matrix material, 3-hydroxypicolinic acid (3-hydroxypyridine-2-carboxylic acid) which showed significant improvement over many previously reported matrices studied in terms of mass range available, signal-to-noise ratio, and the ability to analyze mixed-base oligomers. The desorption and simultaneous ionization was by pulsed laser light at 10 to 50 mJ/cm2, studied at 266, 308, and 355 nm. Spectra taken at 266 nm provided the smallest amounts of doubly charged and dimer ions--characteristics desirable for DNA sequencing by this technology. Negative-ion spectra were uniformly superior to positive-ion spectra. This new matrix also is quite effective for molecular weight determinations of peptides and proteins in both positive- and negative-ion modes.
基质辅助激光解吸飞行时间质谱已被用于从长度为10至67个核苷酸的未衍生化混合碱基单链DNA寡聚物中产生准分子离子信号。这些结果是使用一种新型基质材料3-羟基吡啶甲酸（3-羟基吡啶-2-羧酸）获得的，该材料在可用质量范围、信噪比以及分析混合碱基寡聚物的能力方面比许多先前报道的基质有显著改进。通过10至50 mJ/cm2的脉冲激光进行解吸和同时电离，在266、308和355 nm波长下进行研究。在266 nm处获得的光谱提供的双电荷离子和二聚体离子数量最少，这是该技术用于DNA测序所期望的特征。负离子光谱始终优于正离子光谱。这种新型基质在正离子和负离子模式下对肽和蛋白质的分子量测定也非常有效。
