In-situ SERS readout strategy to improve the reliability of beta-galactosidase activity assay based on X-gal staining in shortening incubation times
- Talanta. 2021 Nov 1:234:122689. doi: 10.1016/j.talanta.2021.122689.
- 1. Institute of Health and Medical Technology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, Anhui, 230031, China; Department of Chemistry, University of Science and Technology of China, Hefei, Anhui, 230026, China; School of Life Science, Anhui University Hefei, Anhui, 230601, China.
- 2. Institute of Health and Medical Technology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, Anhui, 230031, China; Department of Chemistry, University of Science and Technology of China, Hefei, Anhui, 230026, China.
- 3. Institute of Health and Medical Technology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, Anhui, 230031, China. Electronic address: [email protected].
- 4. Institute of Health and Medical Technology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, Anhui, 230031, China; Department of Chemistry, University of Science and Technology of China, Hefei, Anhui, 230026, China. Electronic address: [email protected].
Beta-galactosidase (β-gal) activity is closed related with senescence cells and aging-associated diseases, however, the traditional readout of β-gal activity based on X-gal staining was limited to low sensitivity in short incubation times and false positives in long incubation times. Here, we expose the potential role of insoluble X-gal hydrolysates in causing false positives by diffusion pollution depending on organic medium and then propose the in-situ Surface-enhanced Raman spectroscopy (SERS) readout strategy to identify and locate β-gal positive cells. By building the blue-white screening model and fabricating SERS-active needle sensor, the sensitive detection of β-gal has been realized with the detection limit of less than 1 nmol L-1. The in-situ SERS readout strategy is proved to be necessary and feasible to improve the reliability of X-gal staining assay through shortening the time to a few hours. Moreover, its application was also preliminarily evaluated to analyse individual cells and tissues, which showed the well consistency for judgement of β-gal activity cells at different times. Consequently, by improving reliability and reducing time consumption, this SERS readout strategy may be of great significance to promote the application of X-gal staining assay in biology and biomedicine.