Abnormally high capture ligand binding

Hi, this is my first post in this site.
Questions and answers in this forum are of great help to me. I always appreciate this.

Below is my question.

Abnormally high capture ligand binding is observed intermittently in the capture ligand sensorgram when using His capture kit.

It does not occur throughout the entire cycle. After the cycle occurred, the capture ligand binding level gradually decreased and then returned to normal.

Capture ligand is injected from one vial.

It seems to be improved when the device is desorbed and sanitized.

What do you think about the idea that it is a problem caused by the cleaning of the device?

Can you tell me a reference for this case?

I always appreciate your site and helpful answers. 

Thank you.

What you tell is that the first ligand capture on an anti-His surface gives a high response. The next cycle is lower and then it goes to normal capture levels. Not sure what is abnormally high. Can you give some numbers on capture levels?
My first idea is that the regeneration of the anti-His is not sufficient and you get a decreasing capture level, but I trust you make sure the regeneration is complete.
Stating that the his-ligand comes from the same vial could point to the fact that you loose ligand to the vial wall by adsorption, effectively giving you a lower concentration and therefore a lower capture level. This contradict with the fact that after desorbing and sanitize the problem is less. A clean machine is prone to absorb more protein and you would expect the first capture to be lower.
What happens when you do each capture from a different vial?

Kind regards
Arnoud