Label-Free Method for Cell Counting in Crude Biological Samples via Paramagnetic Bead Aggregation

详细信息    查看全文

• 作者：Jingyi Li ; Qian Liu ; Li Xiao ; Doris M. Haverstick ; Alison Dewald ; Linda Columbus ; Kimberly Kelly ; James P. Landers
• 刊名：Analytical Chemistry
• 出版年：2013
• 出版时间：December 3, 2013
• 年：2013
• 卷：85
• 期：23
• 页码：11233-11239
• 全文大小：374K
• 年卷期：v.85,no.23(December 3, 2013)
• ISSN：1520-6882

文摘

Under chaotropic conditions, DNA released from lysed cells causes the aggregation of paramagnetic beads in a rotating magnetic field in a manner that is independent of the presence of other cellular components. The extent of aggregation correlates with the mass of DNA in a quantitative manner (Leslie, D. C. et al., J. Am. Chem. Soc. 2012, 134, 5689鈥?6), and from this, the number of DNA-containing cells in the sample can be enumerated. Microbial growth testing is demonstrated by monitoring bead aggregation with E. coli in the presence of ampicillin. Without the need for fluorescent labeling or Coulter counting, the white blood cell count can be defined directly from a microliter of crude whole blood. Specificity is brought to the process by coupling bead-based immunocapture with DNA鈥揵ead aggregation allowing for the enumeration of CD4+ T cells from human blood samples. The results of DNA-induced bead aggregation had a 95% correlation with those generated by flow cytometry. With the process requiring only inexpensive, widely available benchtop laboratory hardware, a digital camera, and a simple algorithm, this provided a highly accessible alternative to more expensive cell-counting techniques.