basic liquid handling questions

[granto]

Hi,

I'm injecting into a microscope flow cell.

My main question is, I've got 3 syringe pumps simultaneously pumping injection loop samples (3 X ~25uL ) into a 7-port manifold (~15uL swept vol). Will these samples mix, or will they output as laminar streams? I wanted to avoid agitation because our biological complexes tend to fall apart with shear force.

Another question, since I can't exactly measure it, does anyone have a rough estimate of how much unintentional mixing/dilution will occur between two inline samples? In other words, if I don't want two samples to mix, how much volume should I introduce between the two? I'm using 0.010 ID PEEK tubing if it matters...

Any other tips for a fluidics newbie?

Sorry for the basic questions (and for not knowing the lingo), and thanks for the help

[tom jupille]

It's outside my core area, but the answer is "it depends". On things like:
- flow velocity
- viscosity
- is the tubing straight or coiled, or . . .
- how long is the tubing.

If you want to avoid mixing, find a way to introduce a small air bubble between your injections similar to the old AutoAnalyzer (http://en.wikipedia.org/wiki/AutoAnalyzer)