Gentler Single-Cell Elemental Analysis

A new sample introduction system could boost the accuracy of single-cell elemental analysis by preserving cell integrity and enhancing detection efficiency. The method, which uses a microdroplet generator (µDG) ahead of inductively coupled plasma mass spectrometry (ICP-MS), allows researchers to analyze trace elements in mammalian cells without the structural damage often caused by conventional nebulization techniques.

In single-cell ICP-MS, the standard approach involves introducing cell suspensions via pneumatic nebulizers, which can generate shear stress and compromise cell structures, affecting the accuracy of elemental measurements. In contrast, the gentle nature of the µDG system, developed by researchers at Chiba University, Japan, better maintains cellular integrity, enabling more precise quantification of key elements such as magnesium, phosphorus, sulfur, zinc, and iron.

“Till now, scICP-MS has been applied to bacteria, fungi, plant cells, and red blood cells. We have expanded the potential of scICP-MS technology to mammalian cultured cells, developing a robust analytical technique for measuring elemental content in mammalian cultured cells,” said Assistant Professor Yu-ki Tanaka, in a press release.

The researchers tested the system using K562 leukemia cells, comparing it with traditional concentric glass nebulizers. The µDG method achieved a transport efficiency of over 10 percent, outperforming conventional systems, which struggle with large and fragile mammalian cells. Unlike chemical fixation methods that stabilize cells but alter their elemental composition, the µDG – by gently encapsulating cells in microdroplets before introduction into the ICP-MS system – preserved the native state of the cells, ensuring accurate readings.

“Our findings demonstrate the potential of μDG as a universal sample introduction system in scICP-MS,” said Tanaka. Indeed, the researchers see broad applications for the technique, including environmental monitoring, pharmaceutical quality control, and clinical diagnostics. “One promising social implementation of scICP-MS technology is for the prognosis and diagnosis of diseases,” Tanaka added.