期刊
LAB ON A CHIP
卷 12, 期 11, 页码 2037-2045出版社
ROYAL SOC CHEMISTRY
DOI: 10.1039/c2lc21085a
关键词
-
类别
资金
- National Science Foundation [DMI-0328162]
- National Institute on Drug Abuse [P30DA018310]
- National Institute of Neurological Disease and Stroke [R01NS031609]
- NATIONAL INSTITUTE OF NEUROLOGICAL DISORDERS AND STROKE [R01NS031609] Funding Source: NIH RePORTER
- NATIONAL INSTITUTE ON DRUG ABUSE [P30DA018310] Funding Source: NIH RePORTER
Microfluidic technology allows the manipulation of mass-limited samples and when used with cultured cells, enables control of the extracellular microenvironment, making it well suited for studying neurons and their response to environmental perturbations. While matrix-assisted laser desorption/ionization (MALDI) mass spectrometry (MS) provides for off-line coupling to microfluidic devices for characterizing small-volume extracellular releasates, performing quantitative studies with MALDI is challenging. Here we describe a label-free absolute quantitation approach for microfluidic devices. We optimize device fabrication to prevent analyte losses before measurement and then incorporate a substrate that collects the analytes as they flow through a collection channel. Following collection, the channel is interrogated using MS imaging. Rather than quantifying the sample present via MS peak height, the length of the channel containing appreciable analyte signal is used as a measure of analyte amount. A linear relationship between peptide amount and band length is suggested by modeling the adsorption process and this relationship is validated using two neuropeptides, acidic peptide (AP) and alpha-bag cell peptide [1-9] (alpha BCP). The variance of length measurement, defined as the ratio of standard error to mean value, is as low as 3% between devices. The limit of detection (LOD) of our system is 600 fmol for AP and 400 fmol for alpha BCP. Using appropriate calibrations, we determined that an individual Aplysia bag cell neuron secretes 0.15 +/- 0.03 pmol of AP and 0.13 +/- 0.06 pmol of alpha BCP after being stimulated with elevated KCl. This quantitation approach is robust, does not require labeling, and is well suited for miniaturized off-line characterization from microfluidic devices.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据