I use a DNA/RNA synthesizer from LGC (Biosearch), a MerMade6, to make oligos. The machine has operated for around 16 months and produced about 1500 oligos during this period. As you can see, it is not a heavily used machine.
All preventive maintenances were ok, and the machine was operating just fine and yielding very good quality oligos......
But then it started to present a misalignment between the cart/columns block and the capilaries, pouring reagents out of the columns.
If you look closely you can see that, when the cart with the columns moves and gets to the position assigned, it doesn't stop completely, but slides juuuust a little bit instead. Such a mess!
Calibration doesn't solve the problem: after a calibration, reagents will be delivered correctly into the columns in the first cycle, but as with every move the cart slides a little bit, the misalignment starts to sum up with every move and, at the 3rd cycle, reagents are being spilled outside the columns already.
We are in Brazil. Remotely, LGC team couldn't help. They couldn't even find the problem. The visit of LGC engineering team will coast a lot, and while we are working in resources an bureaucracies to get them here, tips from other users would be welcome and much appreciated.
This machine works with step motor / step motion, which is similar to printers and a lot of other machines. Have you ever seen this kind of issue?
Alternatively, do you know other MerMade users you can put me in touch with?
Thanks in advance
Hi, Andrei Guzaev ... Thanks for the tip! MerMade are LGC Biosearch machines, though... Do you believe Biolytic team will help me with this issue the same way? I know Dr. Oligo Machines are in certain ways similar, but construction wise, a little different either. What are your thoughts on that?
LGC support up to this moment couldn't help remotely. We'll have to bring them here, to Brazil, to figure out what is happening, but while we arrange founding and deal with the bureaucracy, the synthesis is at standby. Makes me sad.
Any insights are much appreciated!
Hi Thaissa. This is an engineering problem, so you have to find an experienced engineer. Biolytic certainly has a different instrument, but it operates on the same principal. They might be able to help. Unfortunately, I don't have any better suggestions. Good luck
Thanks, Andrei, I'll try it! Nothing to loose, and some experience to gain, right? Have a good day!
For anyone interested in the end of this soup opera...
We disassembled the encoder of the stepper motor, and we found aout that the little transparent disk with bars for steps, which should be aligned in the centre of the sensor window, was actually assembled in a way it touched one of the inner faces of the sensor window. It literally touched the plastic. Then, friction caused the bars in the disk to wear out, and dust from this wear was disturbing the sensor, which is why the encoder made mistakes when providing feedback, and ended up causing misalignment (the block reached the point where it should stop, and then the encoder sent the wrong feedback, and the block slid a little more to "correct" the stop position according to the encoder feedback).
It's solved now.
Hi Thaissa, congratulations on exercising great problem solving skills. If you took pictures of the encoder with the disk out of the alignment, it might be a good idea to send those pictures to the manufacturer and request the replacement of the block AT THEIR COST. They may or may not do that, but as the very least, they will pay more attention to this assembly flaw in the future.
Thanks, Andrei!
I certainly did! I took pictures and I have a meeting with them scheduled for tomorrow!
Maybe they won't replace it because the machine is out of warranty... But I'll make some noise anyway, that brought us a lot of trouble!
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