Which company's mouse serum TNF-α ELISA kit has relatively stable recovery rates?

I have used R&D Systems Mouse TNF-α Quantikine; spike recovery in serum is typically 90-110%. For bronchoalveolar lavage fluid, if protein is low, it is recommended to reduce dilution or load the sample neat. Within a budget of 2500, it is difficult to buy a full R&D kit; you can look for distributors to purchase the 48T format or pool orders. Among domestic brands, Lianke and Xinbosheng show batch-to-batch variability in recovery that you need to verify yourself. When selecting, focus on whether the low point of the standard curve covers around 7.8 pg/mL. Do not default to large-fold dilution for serum samples; for cell supernatants, it is recommended to first run a 1:2 or neat pilot test.

Your sample size is not large, so try to complete the measurements within the same batch to avoid cross-batch variation. TNF-α in mouse serum and bronchoalveolar lavage fluid often falls in the low-value range, so it is recommended to choose a kit with a lower detection limit, for example, a specification whose lowest standard point can reach 7.8 pg/mL or lower; if the standard curve starts at 15.6 pg/mL, low values will be relatively difficult. Within a budget of 2500, imported original products may not necessarily be sufficient, but you can look at ready-to-use small specifications from BioLegend and Invitrogen or high-end domestic lines. After arrival, use 2-3 serum samples and cell supernatants for dilution linearity to determine whether they fall within the standard curve.

Don't just look at the brand; focus on three parameters: linear range, validated sample types, and matrix spike recovery reference. Prioritize kits whose instructions explicitly state "validated for mouse serum/plasma," and ask the sales representative to provide spike recovery data from recent lots. Domestic first-tier brands under 2500 can usually meet the requirements; for imported brands, you can look for near-expiry promotions but pay attention to the expiration date. If bronchoalveolar lavage fluid and cell supernatant are not among the validated sample types, you must perform your own spike validation. Recovery is recommended to be controlled within 80-120%; if below 80%, investigate matrix interference or dilution factors.

Previously, the spiked recovery in serum was only over 70%, possibly because the standard diluent was not consistent with the serum matrix, or endogenous TNF-α was not subtracted. When performing spike recovery, it is recommended to set up a blank tube with the same serum, then add low, medium, and high concentrations, and subtract the background during calculation. For domestic kits, mouse TNF-α 96T from Xinbosheng, Dakewe, and Lianke is mostly around 2000-2500, and you can ask the sales representative to provide a recent batch COA. TNF-α in bronchoalveolar lavage fluid is usually low, so do not follow the instructions for 1:5 dilution; it is recommended to try 1:2 or neat first.