50% Glycerol w/FCA & MCA

Hi All!

I’m looking to optimize a liquid class on the Fluent using the liqFCA and MCA, and was curious if anyone has experience with 50% glycerol and 50% aqueous solutions. Both cold and room temperature may be used.

Typically I’ve been aspirating slow and dispensing fast with a delay with slow retraction at volumes of 2-1000 uL, and am new to the Tecan so I am open to ideas.

Thanks in advance!

What’s your hang up?

A pretty viscous mixture that can be anywhere from 4C to 20C, getting consistent volumes within that 2-250 uL with the 1mL FCA even when utilizing the Fluent’s AdjustAccuracy command has gotten me pretty close. Do you have any experience doing something like this?

There are some tricks to doing this well as aspiration need to be slow and large delays. All kudos to Alf Price, a legend in Liquid Class optimisation at Tecan, for teaching me this. He had developed a method of aspirating and dispensing 50% glycerol for master mix preparation and was able to multi dispense down to 2.5ul x8 with airFCA and 50ul tips. Done with great accuracy and precision into dry wells before adding other components.

He used a technique of over dispensing into a PCR well then removing the know excess you naturally get from the droplet. This left a more accurate volume in the well with very viscous solutions due to the variance between aspiration and dispense. Obviously your z-max has to be taught well and the tip cannot be reused. This was done on a Fluent so the macroscripts could be tuned for these movements and volume calculations in one go but on an EVO you may have to split this into two separate cycles with variable for volumes.

If really need this to work at small volumes then I would contact Tecan help desk and get them to contact Alf to see if he has time to help or he might be able to share the liquid class he built.

I imagine MCA is also possible as this would a single over dispense and the a correction aspiration.