What does a 1:200 dilution actually mean?

It means one part antibody made up to 200 total parts. So in a 1000 microlitre working solution you add 5 microlitres of stock antibody and 995 microlitres of diluent. The tool does this arithmetic and adds your dead volume on top.

Why add a dead volume?

Pipetting loss, evaporation, and the need to fully cover each section mean you should prepare a little more than the bare minimum. The dead volume is a small overage so you never run short on the last slide.

Can I work from concentrations instead of a ratio?

Yes. Enter the stock concentration in mg/mL and the target working concentration in micrograms per millilitre. The tool converts the stock to the same units and divides to find the dilution factor, then computes the volumes from there.

How do I choose the right dilution?

Manufacturers suggest a starting range, but every new lot and tissue should be titrated. Run a small series such as 1:100, 1:200, and 1:400 and pick the dilution that gives strong specific signal with the least background. This tool gives you the exact volumes for each test point.

Does this apply to both IHC and ICC?

Yes. The dilution mathematics is identical for tissue sections in immunohistochemistry and cultured cells in immunocytochemistry. Only the volume per sample and the diluent chemistry differ, both of which you set as inputs.

Antibody Dilution Calculator for IHC / ICC

Primary and secondary antibodies for immunostaining are supplied concentrated and must be diluted into a working solution before they touch tissue. Getting the volumes exactly right saves expensive reagent and keeps staining reproducible. This calculator turns a target dilution and a batch size into precise pipetting volumes.

How it works

A dilution written as 1:N means one part antibody brought up to N total parts. In a chosen working volume V the split is simply:

antibody volume = V / N
diluent volume  = V - (V / N)

The working volume itself is driven by how many sections you are staining plus an overage so you never run dry:

V_total = (sections x volume_per_section) + dead_volume

If you would rather work from concentrations, the tool derives the dilution factor by putting both into the same units:

N = stock(ug/mL) / target(ug/mL)
  = (stock_mg/mL x 1000) / target_ug/mL

Example and notes

To stain 10 sections at 100 microlitres each with a 50 microlitre overage, the total working volume is 1050 microlitres. At 1:200 that is 5.25 microlitres of antibody made up with 1044.75 microlitres of diluent. Always titrate a new antibody lot across a small dilution series and choose the point with the strongest specific signal and the cleanest background; this tool gives you the exact volumes for each test dilution.