Biomek Guide

Streaming Biomek

Friday, July 20, 2007


1. I am now able to do a variable liquid level aspirate using a csv input
2. The robot is up and running on an agar dispense function and seed dispense for 96 well plates.

The first is only of interest to me or those who have to dilute a lot of powdered chemicals in a 96-well format. The second point is of interest to all.

In short the Biomek can make 96 well chemical screening assay plates from start to finish. This includes the addition of seeds to a desired final number per well (here 12-20 seeds per well).

The agar dispense was the hardest function to perfect. With a hot water wash of the tips after each agar aliquot the agar retension due to high viscosity (I use 0.67% agar) is overcome.

The 96-well seed dispense is achieved using wide bore tips. The 96-head aspirates from a seed suspension and then aliquots directly into the 96-well assay plate onto the hardened agar.

More interesting things to come:

1. single seed dispense to 96-well plates
2. dual seed dispense to 96-well plates. Side-by-side!
3. Pin tool chemical treatment of agar perfused with yeast.
4. ???

Technical updates from Phil's latest repair:

96 Multichannel Pod

1. pod was dropping in z axis following light curtain interuption/mag brake not
working/ I found a loose setscrew on the mag brake and resecured - fixed.

2. Pod not parallel to deck/ pod cocked towards rear in y axis a small amount/ I
releveled pod and reframed deck for MC pod

Span8 Pod

1. I realigned probes and reframed deck - much better alignment now. I also
realigned some of the tip detect black boxes which were slightly angled.

2. I did not experience any tip detect problems, but I ran relatively few tips.
Keep an eye on this and let me know if you have any more problems. Make sure
that none of the black shuck tubes or mandrel collars are loose.

3. I did not experience "probe spitting" (large droplets) but did notice "probe

I noticed what I call "probe misting" where very,very small droplets of system
fluid mist from the end of the mandresl. I believe these are unrelated to the
larger droplets of "probe spitting" generated within the mandrel and system
tubing, but result from droplets of fluid that form on the mandrel tip during
the purge cycle. and attach between the nipple and body of the mandrel.The
mandrels have a very short nipple, and purged fluid frequently bridges. I
believe the misting that I mention above is the result of this residual fluid
misting as the air quickly moves in and out of the nipple during and aspirate or
dispense cycle. See diagram below. You can minize this bridged fluid by cleaning
the ends with alcohol. Otherwise, I can't suggest anything.

Remember to use a slower asp/disp speed (50ul/sec?) to prevent probe spitting.

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