Ca²⁺ is among the most important intracellular second messengers participating in a plethora of biological processes, and the measurement of Ca²⁺ fluctuations is significant in the phenomenology of the underlying processes. Aequorin-based Ca²⁺ probes represent an invaluable tool for reliable measurement of Ca²⁺ concentrations and dynamics in different subcellular compartments. However, their use is limited due to the lack on the market of ready-to-use, cost-effective, and portable devices for the detection and readout of the low-intensity bioluminescence signal produced by these probes. Silicon photomultipliers (SiPMs) are rapidly evolving solid-state sensors for low light detection, with single photon sensitivity and photon number resolving capability, featuring low cost, low voltage, and compact format. Thus, they may represent the sensors of choice for the development of such devices and, more in general, of a new generation of multipurpose bioluminescence detectors suitable for cell biology studies. Ideally, a detector customized for these purposes must combine high dynamic range with high fidelity in reconstructing the light intensity signal temporal profile. In this article, the ability to perform aequorin-based intracellular Ca²⁺ measurements using a multipurpose, low-cost setup exploiting SiPMs as the sensors is demonstrated. SiPMs turn out to assure performances comparable to those exhibited by a custom-designed photomultiplier tube-based aequorinometer. Moreover, the flexibility of SiPM-based devices might pave the way toward routinely and wide scale application of innovative biophysical protocols.

中文翻译：

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评估基于硅光电倍增管的平台，用靶向水母发光蛋白测量细胞内钙动力学。

Ca ²⁺是参与过多生物学过程的最重要的细胞内第二信使，并且Ca ²⁺涨落的测量在潜在过程的现象学中是重要的。基于水母发光蛋白的Ca ²⁺探针是可靠测量Ca ²⁺的宝贵工具不同亚细胞区室的浓度和动力学。然而，由于市场上缺少用于检测和读出由这些探针产生的低强度生物发光信号的现成的，具有成本效益的便携式设备，因此它们的使用受到限制。硅光电倍增器（SiPM）是发展迅速的固态传感器，用于低光检测，具有单光子灵敏度和光子数解析能力，具有低成本，低电压和紧凑的格式。因此，它们可以代表用于开发这种设备的传感器，并且更广泛地代表用于细胞生物学研究的新一代多功能生物发光检测器。理想情况下，为此目的而定制的检测器在重建光强度信号的时间分布时必须结合高动态范围和高保真度。在本文中，执行基于水母发光蛋白的细胞内钙的能力演示了使用SiPM作为传感器的多功能，低成本设置的²⁺测量。事实证明，SiPM可以确保性能与定制设计的基于光电倍增管的测湿仪相媲美。此外，基于SiPM的设备的灵活性可能为常规的创新生物物理协议的大规模应用铺平道路。