Cole Jacquelyn R, Dick Lawrence W, Morgan Elizabeth J, McGown Linda B
Department of Chemistry and Chemical Biology, Cogswell Building, Rensselaer Polytechnic Institute, Troy, New York 12180, USA.
Anal Chem. 2007 Jan 1;79(1):273-9. doi: 10.1021/ac061256b.
Capture and detection of immunoglobulin E (IgE) in simple solution and in human serum using an aptamer-modified probe surface for affinity matrix-assisted laser desorption/ionization mass spectroscopy detection is reported. Detectable signals were obtained for 1 amol of IgE applied either in a single, 1microL application of 1 pM IgE or after 10 successive, 1-microL applications of 100 fM IgE. In both cases, the surface was rinsed after each application of IgE to remove sample concomitants including salts and free or nonspecifically associated proteins. Detection of native IgE, which is the least abundant of the serum immunoglobulins and occurs at subnanomolar levels, in human serum was demonstrated and interference from the high-abundance immunoglobulins and albumin was investigated. The aptamer-modified surface showed high selectivity toward immunoglobulins in serum, with no significant interference from serum albumin. Addition of IgE to the serum suppressed the signals from the other immunoglobulins, confirming the expected selectivity of the aptamer surface toward IgE. Dilution of the serum increased the selectivity toward IgE; the protein was detected without interference in a 10,000-fold dilution of the serum, which is consistent with detection of IgE at amol (pM) levels in standard solutions.
报道了使用适配体修饰的探针表面进行亲和基质辅助激光解吸/电离质谱检测，以捕获和检测简单溶液及人血清中的免疫球蛋白E（IgE）。无论是单次1 μL 1 pM IgE的应用，还是10次连续1 μL 100 fM IgE的应用，施加1 amol IgE均可获得可检测信号。在这两种情况下，每次IgE应用后均冲洗表面，以去除包括盐以及游离或非特异性结合蛋白在内的样品伴随物。证明了在人血清中检测天然IgE（血清免疫球蛋白中含量最少且以亚纳摩尔水平存在），并研究了高丰度免疫球蛋白和白蛋白的干扰。适配体修饰的表面对血清中的免疫球蛋白具有高选择性，血清白蛋白无明显干扰。向血清中添加IgE会抑制其他免疫球蛋白的信号，证实了适配体表面对IgE预期的选择性。血清稀释增加了对IgE的选择性；在血清10000倍稀释时检测到该蛋白且无干扰，这与在标准溶液中检测amol（pM）水平的IgE一致。
