The problem of large inter batch differences in mouse TNF - α ELISA kit

If the difference between batches exceeds 20%, don't rush to blame the box. The common reasons for the overall drift of the standard curve OD are inconsistent reconstitution of the standard product, residual washing solution, failure to freeze the color development temperature and time, or differences in incubation time between different batches. Suggest sorting out the three batches of original OD to see if they are overall translation or high concentration point drift; After the same batch of standard samples is packaged and frozen, they should be retested simultaneously. If the operation is ruled out, then determine if it is a batch issue. It also depends on whether the standard is prepared every time, as there may be differences between different batches of standard.

After receiving the new kit, perform a bridging study using the same batch of cell supernatant and the remaining standards from the old kit. Select 3-5 concentrations covering low, medium, and high levels, and run both old and new kits in parallel to assess systematic bias and correlation. If samples are insufficient, spike-and-recovery can be used: add standards to supernatant of known concentration and check the recovery rate. Only proceed to formal samples after passing this validation. If throughput is low, it is recommended to purchase strip-well plates that can be broken apart, using 8 wells at a time to avoid opening the entire plate. If delivery can be made within one week, prioritize local agents with stock available.

<p>Before switching brands, ask the distributor to provide the quality control report for the target lot number; do not rely on official website promotional claims. The key is to examine the inter-batch CV and intra-batch CV, usually inter-batch</p>

Sales are required to do three things: provide the spot batch number, corresponding COA, and promise to reserve or send the same batch number in the future. Domestic manufacturers such as Lianke, Dakewei, Sizhengbai, Xinbosheng, etc. have many prefecture level agents, and they can generally meet the delivery requirements within a week. However, it is important to ask if they can ship from local warehouses, as cross regional shipments may take 1-2 more days. Don't stockpile too many batches at once within the budget range. Buy one box for verification first, confirm stability, and then replenish with the same batch number. Ask the sales team to include the inter batch CV and delivery time in the contract/communication record, and refunds can be made if they do not meet the standards.