No detection/bulk on FC1 but Fc2 works perfectly

Hi
Could anyone please suggest a solution to the following.

1. We recently had a preventative maintenance kit installed on our BIAcoreX (new IFC/ Opto-interface etc)

2. Docking a new CM5 chip, Signal Quality Check shows OK signal on both flow cells and performing System Check with 15% BIAtest in HBS resulted in no bulk refraction in the serial flow ([Sample]---->Fc1--->Fc2---->Waste) and no bulk refraction on Fc1 in the sequential ([Sample]---->Fc1---->Waste; Fc2 microvalve closed) but a positive bulk refraction on Fc2 in the sequential system check ([Sample]---->Fc2---->Waste, Fc1 microvalve closed).

Could it simple be due to a sticky microvalve for flow path 1/Fc1 if so multiple Unclog and IFC washes do not solve the problem.

Is it possibly just a faulty new IFC from BIAcore/GE Healthcare, is this common.

Has anyone encountered it before, how did you solve it short of installing a new IFC?

Thanks for any help, it would be greatly appreciated
Earl

Hi,

Did FC1 work immediately after installing the IFC?

If unclog does not help, does docking a new chip help?

The microvalves are opened/closed by air pressure. But the strange thing is that they are closed by air pressure and open on release.
Can you check the air pressure (I'am not familliar with the Biacore X)?

If it is not released, mayby soemthing went wrong during installing the new IFC.

kind regards

Arnoud

Hi Arnoud
Thanks for the reply.
Fc1 did not work immediately after. I docked a new CM5 chip and let it run overnight to equilibrate. The following day I ran multiple unclogs and IFC washes, still no luck. After undocking the CM5 chip and redocking the maintenance chip I ran a desorb, redocked the CM5 chip and ran a system check following prime and rinse. The system check ran perfectly, at which point I thought everythings fine and I checked the liquid handling by performing multiple injections at fixed volume and different flow rates. I then put the machine into close over the weekend and continued yesterday which is when it reverted back to no detection on Fc1. The machine appears to be operating at optimal pressures. I have noticed some condensation this afternoon in the airtubing from the Pressure control to the IFC (the 8channel rubber/silicon tubing), could this be the problem.
Thanks for the reply in helping me understand this issue.
Its greatly appreciated.
Regards,
Earl

Hi Earl,

As I mentioned, I am not familiar with the Biacore X.
You write that after changing the IFC it did not work. Did you change it your self? It sometimes happens that an IFC is faulty from the beginning.

I think the condensation in the pressure tubing is not good. Is there a kind of liquid trap/condensation unit in a Biacore X. If so, maybe it is full or malfunctioning. I am not sure how to get the condensation out but can imaging that is wil interfer with the valves depending on the temperature of the machine. As you said, after a weekend it did not work, after cleaning is did.

Arnoud

Hi
Thanks for the reply.
The IFC was installed by the BIAcore South African representative sales company technician (Separation Scientific). He however admitted that its the first time that he has encountered this type of machine.

A little background on the machine regarding the condensation trap. As a result of the installation of a new valve block last year the condensation trap is now housed outside the machine. We check it for moisture regularly and it tends to accumulate during the days runs, usually at the point the trap is emptied and dried before continuing. I have a sneaky suspicion that there maybe accumulated moisture in the tubing that maybe affecting Fc1 valve control. The technician is due to return this week and I'll have him check the tubingfor any moisture.

Thanks for the help and keep well
Regards,
Earl