How to determine the dilution ratio and batch difference of MCE antibody by Western blot?

If the bands become weak, don't rush to request a return or exchange. Organize the original WB image, marker, sample information, primary antibody catalog number and lot number, dilution ratio, and incubation conditions, then contact MCE technical support. They will usually perform troubleshooting first, such as recommending adjustments to the blocking solution, antibody diluent, secondary antibody concentration, or development time. If obvious abnormalities remain after investigation, you can request after-sales evaluation to determine whether it is a quality issue. Whether a return or exchange is possible depends on the specific policy and whether it is within the warranty period, but generally, if it is confirmed to be a batch issue with the product itself, the supplier will arrange a replacement or refund. Be sure to keep the unused antibody and COA.

The specification dilution ratio is only the starting point. After changing the batch, I usually do a gradient mapping. Taking 1: 1000 as the center, try 1: 500, 1: 1000, and 1: 2000 respectively, and prolong the incubation of primary antibody to 4 ℃ overnight if necessary; the loading volume of 30μg remains unchanged, while running internal reference, so as to distinguish whether it is a decrease in antibody titer or a problem of membrane transfer/development. The weak signal may also be related to the blocking solution, the washing time or the ECL substrate. It is recommended to run the new and old batches side by side under the same conditions to see the trend before adjusting.

There may indeed be some differences between different batches of the same product number, with multiple antibodies being more pronounced and monoclonal antibodies being relatively stable but cannot be completely ruled out. After the new batch arrives, first check the batch, recommended dilution ratio, and expiration date on the COA, and check the storage conditions. Repeated freezing and thawing of antibodies or exposure to room temperature can cause a decrease in signal. If you still have old batches on hand, keep some for head to head comparison; If the new batch needs to increase the concentration to reach the old batch signal, record the replenishment ratio clearly and indicate the batch in the report.