How to use the gel molecular weight calculator
Estimate band size from migration distance using two markers. Enter band relative mobility rf, marker 1 rf, marker 1 mw, marker 2 rf, marker 2 mw in the fields above; the estimated mw is computed instantly and plotted on the chart so you can see how the answer changes.
Formula
Variables
- rf — Band relative mobility Rf
- rf1 — Marker 1 Rf
- mw1 — Marker 1 MW (kDa)
- rf2 — Marker 2 Rf
- mw2 — Marker 2 MW (kDa)
Worked example
With band relative mobility rf = 0.5, marker 1 rf = 0.2, marker 1 mw = 100 kDa, marker 2 rf = 0.8, marker 2 mw = 20 kDa, the calculator gives estimated mw ≈ 44.72136 kDa.
Frequently asked questions
What is the formula for the gel molecular weight calculation?
Estimated MW (kDa) = 10^(log10(mw1)+(rf-rf1) × (log10(mw2)-log10(mw1)) / (rf2-rf1)). Here rf is band relative mobility rf, rf1 is marker 1 rf, mw1 is marker 1 mw (kDa), rf2 is marker 2 rf, mw2 is marker 2 mw (kDa).
What inputs do I need for the gel molecular weight estimator calculator?
You need band relative mobility rf, marker 1 rf, marker 1 mw in kDa, marker 2 rf, marker 2 mw in kDa. Each field is pre-filled with a typical example so you can see how the result responds as you edit the numbers.
How do I use this calculator?
Type values into the input fields. Results and the chart update instantly. Use Reset to restore the example values, Copy results to paste them elsewhere, or Share to copy a link that preserves your inputs.
Is the result exact?
Calculations use standard formulas and double-precision arithmetic, then display about seven significant figures. Real-world measurements carry uncertainty, so treat results as estimates unless your inputs are exact.