Hi David, 

We tried to use Covaris system for RNA sharing and it was not great for our RNA applications: system is complicated and expensive, sonication was long for us.

Covaris E/LE systems allow you to use up to 96 samples at once. They have smaller systems, which are newer and probably better.

Branson system is cheap, but 1 sample/time.

Thanks,

Alex

I have tried both covaris E220 system and biorupture from diagenode, both multisample. Biorupture is better as it is quick to shear chromatin. To reach a 200 bp fragment length by shearing with covaris I needed 35 min per sample using the parameters for chromatin shearing recommended by covaris, total took 7 hours so I don't recommend it.

I used the Bioruptor (with a holder for 6 samples) also for tissues, that worked good. Sometimes we had some general problems though with our instrument.

Bioruptor is fine, depends on the tube size, I think you can process up to 6 samples at one time if not mistaken. I tried in cell culture and took like 30cycles to get 400bp fragments. Other than that, with fisher sonicator I can get a 200 bp fragments in 70% amp, for 5-6 cycles, each 30secs pulse, 30secs rest, but of course you can only process 1 tubes each time, but I think this can be adjusted via increasing to 90% amp. Usually I cool the probe with ice bath for a min every 5 cycles to avoid over-heat.

I used Bioruptor as well and it always worked fine for me. It required a bit of optimisation at the beginning to get it down to the size fragment I was looking for (300-350bp). With cell extract from a sponge species I am happy with 12-15 cycles 30s ON and 30s OFF. You can use a holder for 6 samples. I do too cool the water with ice every 5 cycles to avoid over-heat. 

Has anyone tried the Q800R1 Sonicator instrument for tissue chromatin (or any chromatin preparation)?

http://www.activemotif.com/catalog/780/q800r1-sonicator

I would recommend a bioruptor. Yes it requires some optimizations but it's true for any sharing system and new cell model. Anyway it's better to perform a tight control of your chromatin sharing to make sure that your device and protocol are working before trying any subsequent assay