How to choose an ELISA kit for the detection of IL-6 and TNF-α in mouse serum?

When choosing a kit, don't get hung up on the brand first. Check whether the sample types and detection range clearly specify mouse serum and EDTA/heparin plasma, and ask the manufacturer to provide spike recovery data in serum matrix. For 80 samples at 50 microliters each, if both targets are run in duplicate, it is advisable to first evaluate 2 small-format 48T or 96T kits rather than going straight to bulk packaging. I usually take 3-5 representative serum samples and run 2-fold and 5-fold dilution linearity to see whether IL-6/TNF-alpha fall in the middle of the standard curve. Imported products usually have a lead time of 2-4 weeks, while domestic ones commonly take 3-7 days, and small formats can mostly be purchased first. In terms of stability, major imported brands have more controllable lot-to-lot variation, but this is not absolutely necessary.

I use both domestic and imported products. If it is only for internal comparison within a research group and completed with the same batch of kits, domestic single-factor kits such as those from Lianke and Xinbosheng are usually sufficient and reasonably priced; however, if data need to be compared across batches or accumulated over the long term, imported R&D, BioLegend, and BD products have advantages in batch-to-batch stability. Before purchasing, it is advisable to ask the sales representative to provide a mouse serum validation report for the corresponding target, focusing on sensitivity and inter-assay CV. In terms of lead time, imported small-pack sizes that are in stock domestically may arrive in 1-2 weeks; if not in stock, it takes 4-6 weeks, while domestic in-stock products such as Lianke are very fast. You can first buy a 48T small-pack size, but do not skip the preliminary experiment, especially for TNF-α, which sometimes needs to be measured after dilution.

It is not advisable to directly ask which brand is better. Measuring two indicators at the same time makes the sample volume a bit tight: for duplicate wells, 50-100 microliters per well. For 80 samples with both indicators measured in duplicate, at least 160 wells are needed, and a single 96T box may not be enough. It is recommended to calculate the number of wells, dilution factors, and replicates clearly. You can consider the manufacturer's small-size trial pack or half-plate strip packaging to reduce trial-and-error costs. I place more importance on linear dilution recovery and the lower limit of quantification in low-value serum. IL-6 has low baseline levels in mouse serum, so sensitivity requirements are high. When ordering, ask the sales representative to confirm the in-stock lot number to avoid transfer arrangements after shipment. If imported boxes are transferred from abroad, around 4 weeks is also common recently; domestic ones are generally within 1 week. Try a small size first, and after it is stable, replenish with a large box of the same lot number.