Western Blot Antibody Dilution Calculator

An antibody dilution calculator is a tool that helps researchers determine the optimal dilution ratios for primary and secondary antibodies in immunoassays. It calculates the exact volumes of antibody stock and diluent needed to achieve the desired working concentration for applications like Western blotting, ELISA, and immunofluorescence.

Primary antibodies for Western blot are typically diluted between 1:500 to 1:10,000, with 1:1,000 being most common. Secondary antibodies are usually diluted between 1:2,000 to 1:10,000. The optimal dilution depends on antibody affinity, protein abundance, and detection method.

Start with manufacturer recommendations, then optimize through titration experiments. Test a range of dilutions (e.g., 1:500, 1:1000, 1:2000, 1:5000) to find the dilution that gives the strongest specific signal with minimal background.

Common buffers include TBS-T (Tris-buffered saline with Tween-20), PBS-T (phosphate-buffered saline with Tween-20), or specialized blocking buffers containing BSA, milk, or other blocking agents. The choice depends on your specific protocol and antibody requirements.

Diluted antibodies generally have reduced stability compared to concentrated stocks. Primary antibodies can often be stored at 4°C for a few days to weeks, while secondary antibodies should preferably be used fresh. Always add preservatives like sodium azide for longer storage.

Proper dilution ensures optimal signal-to-noise ratio, prevents antibody waste, and maintains experimental reproducibility. Over-concentrated antibodies can cause high background, while under-diluted antibodies may give weak signals and poor sensitivity.

Different techniques require different dilutions: Western blot (1:1000-1:5000), ELISA (1:1000-1:10000), immunofluorescence (1:100-1:1000), and immunohistochemistry (1:50-1:500). The detection method sensitivity and sample preparation affect optimal concentrations.