Title: Ultra-sensitive and stable performance with Whisper Flow Technology

Journal: Evosep Application

Date：2021.01

Abstract:

Whisper is the latest Evosep One innovation that allow plug-and-play, split-free 100 nl/min performance. The new methods make use of Evosep’s unique low pressure gradient formation and very accurate flow control on the same standard system without technical modifications. The gradient is built and stored in the loop in the low pressure part of the system and then pushed to the analytical column using the high pressure pump, allowing for accurate gradients at very low flow. The Whisper methods are designed for ultra high sensitivity applications, where sample amounts are very limited.

The methods are freely available through a software upgrade for standard Evosep One hardware, while optimized columns and emitters are required.

Whisper是最新的Evosep One创新，可实现即插即用、100 nl/min的性能。新方法利用了Evosep独特的低压梯度地层，并在同一标准系统上进行了非常精确的流量控制，无需进行技术修改。梯度被建立并存储在系统低压部分的回路中，然后使用高压泵推送到分析柱，从而在非常低的流量下获得准确的梯度。Whisper方法专为样品量非常有限的超高灵敏度应用而设计。

这些方法可通过标准Evosep One硬件的软件升级免费获得，同时需要优化柱和发射器。

Whisper 20SPD和40SPD

Whisper Flow Technology为超低流量纳米LC带来了较好的稳健性，使其能够在同一发射器和同一柱上运行数千次。45天的一系列连续测试证明了这一点。从上千次运行中，只观察到柱压随时间略微增加。

图1：数千次运行的高压泵压力和流量曲线显示，随着时间的推移，背压略有增加。

Evotips是基于C18的一次性捕集柱，能完全捕获低样本量，比从进样小瓶中重复吸取更有效。与C18结合的肽相当稳定，可以冷藏30天。最后，部分洗脱通过在Evotip上留下非常疏水的分子，如脂类和污染物，提高信噪比。

Brunner AD., Thielert M., Vasilopoulou C., Ammar C., Coscia F ., Mund A., Hoerning O., Bache N., Apalategui A., Lubeck M., Raether O., Park MA., Richter S., Fischer DS., Theis FJ., Meier F ., Mann M. (2020) Ultra-high sensitivity mass spectrometry quantifies single-cell proteome changes upon pertubation. https://www.biorxiv.org/content/10.1101/2020.12.22.423933v1