haven_t 发表于 2012-4-10 14:43
也有道理，不过关键是所谓的速度是指哪个地方的速度，检测去的速度还是两种液体混合前的速度。还有个问题 ...
从这篇文章来看，应该是鞘液速度可调，说明平时调的HIGH、MEDIUM、LOW，我们平时常用的机器都是利用鞘液流带动样本。
http://www.theflowguy.com/Fluidics.php
This fast flowing sheath produces a huge drag effect on the core chamber, this drag leads to the dispersed sample to be pulled into alignment; this effect is known as hydrodynamic focusing. In this jet-in-air flow chamber, once aligned the sheath and the sample are forced parallel out of the flow chamber under laminar flow conditions ready to be interrogated as they flow past the light source.
In laminar flow the sample and sheath do not actually mix (well, on some ionic level as seen with PI staining, but for practical purpose we can say they do not mix). The difference between the sample and sheath pressure is known as the sample differential. The greater the sample differential the faster the sample will flow in to the flow chamber, this will increase the event rate, or number of cells interrogated in any given time. The speed at which the sample is forced into the flow chamber is known as the flow rate. How well aligned the cells are when delivered to the interrogation zone depends on the flow rate! If you look at the diagram below, the X shows the spot where you want to pass a cell. You can see, at slower flow rates the inner "core" sample stream is small so cells are reproducibly passed through this point.
| 
发表于 2012-4-10 14:43:47
发表于 2012-4-12 10:05:18
浙ICP备17054466号-2