Antibody analysis with size exclusion

[chromochat]

I am working with an antibody. It seems like that the antibody is not stable in the mobile phase (diluent) during the size exclusion analysis (autosampler temp: 2-8C). Mobile phase is a 10 mM Sodium Phosphate, 700 mMSodium Chloride, pH 6.1 ± 0.1.
I am not able to run more than 12 injections of the antibody between system suitability injections. Any suggestions on how I can improve the stability of the antibody in the mobile phase so that i can run more samples in one sample set?

[danko]

How does this instability manifest itself? Please describe what you’re seeing.

Best Regards

[chromochat]

I am working with an antibody. It seems like that the antibody is not stable in the mobile phase (diluent) during the size exclusion analysis (autosampler temp: 2-8C). Mobile phase is a 10 mM Sodium Phosphate, 700 mMSodium Chloride, pH 6.1 ± 0.1.
I am not able to run more than 12 injections of the antibody between system suitability injections. Any suggestions on how I can improve the stability of the antibody in the mobile phase so that i can run more samples in one sample set?

There is a decline in aggregate level within a run(same day). It looks like sample degrades over a 15 hrs period.

[danko]

It seams to me that you’re “problemâ€

[chromochat]

Thanks danko. I will play with the pH and salt concentration.

[Uwe Neue]

Well, the question is: what is an aggregate? If the aggregation is reversible within the time frame of a day, it is not a permanent aggregate. The people in your formulation department might be interested in your findings. Maybe a change in formulation could prevent aggregation?

[HW Mueller]

Is this an IgG? I have worked with several commercially available Mab of this type and have never seen a problem with aggregation. From this I assumed that handling these is well established for analysis and for the purpose of their use.
Could it be that your “aggregationâ€