In mice, usually 7 days post SRBC immunization, Abs will get to the peak. I guess chicken has different responding time window. But there's a nice paper did some prelim study on chicken with SRBC.

Please see a paper titled: Antibody responses to different dosages of sheep red blood cells in lines of chickens selected for high and low antibody response to sheep red blood cells.

This paper has a nice figure showed the Ab titer on different dates after SRBC immunization.

Also, not sure what you mean about the time to collect tissues. If a specific gene for Abs initiation is defect, there won't be enough Ab made, blood serum Ab anti-SRBC elisa could tell this. More specifically, is the particular gene important for all types of Abs or important for Ab isotype switching...

Thank you Markus for your suggestion. We are still not sure about the function of this particular gene in antibody production, but can only assume its role in antigen presentation and recognition in innate immune system, so we need to select a time of investigation even before the antibody being produced.

Dear Jibin,

please carefully consider the hypothetical role of your particular gene and how this relates to the read out you generate from the immunization experiments. The choice of antigen can be critical as e.g. polyvalent and particulate antigens are known to be less dependent / independent of t-helper cell support. Along similar lines presentation by dentritic cells maybe less or more important. Depending on the suspected role of your particular gene you may want to chose different immunogens and vaccination strategies.

Best Markus