Antibody Titer Calculator

The Antibody Titer Calculator calculates exactly how much antibody stock and buffer to combine when preparing a working solution at a specific concentration — useful in immunology, diagnostics, and lab research. Enter your stock antibody concentration, desired final concentration, and total volume needed to get the antibody volume and buffer volume required. You can also configure a serial dilution series by selecting a starting dilution, dilution factor, and number of steps to see the full dilution scheme and calculated titer.

Results

Antibody Volume Needed

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Buffer Volume Needed

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Dilution Ratio

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Calculated Titer

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Results Table

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Frequently Asked Questions

What is an antibody titer and why is it important?

An antibody titer is the highest dilution of an antibody solution that still produces a detectable signal. It helps determine the optimal concentration for experiments and ensures reproducible results while minimizing background noise.

How do I choose the right starting dilution for my antibody?

Start with the manufacturer's recommended dilution range, typically 1:100 to 1:1000 for primary antibodies. If no recommendation exists, begin with 1:100 and perform a serial dilution to find the optimal concentration.

What's the difference between primary and secondary antibody dilutions?

Primary antibodies bind directly to your target protein and are typically used at 1:100-1:5000 dilutions. Secondary antibodies bind to primary antibodies and are usually more concentrated, requiring higher dilutions of 1:1000-1:10000.

How many serial dilutions should I include in my experiment?

Include 6-8 dilution points spanning 2-3 log orders to capture the full dynamic range. This ensures you find both the optimal working dilution and the point where signal drops to background levels.

What dilution factor should I use between serial dilution steps?

Use 2-fold or 3-fold dilutions for fine titration when working near the optimal range. Use 5-fold or 10-fold dilutions for broader screening or when you need to cover a wider concentration range quickly.

Can I store diluted antibodies for future use?

Avoid storing diluted antibodies when possible, as dilution reduces stability. If storage is necessary, add BSA or glycerol as stabilizers, store at 4°C, and use within 24-48 hours for best results.

How do I calculate the volume of stock antibody needed for my dilution?

Use the formula C1×V1 = C2×V2, where C1 is stock concentration, V1 is stock volume needed, C2 is final concentration, and V2 is final volume. This calculator automates this calculation for you.