Assay is a fast bench calculator for scientists — protein and oligo properties, molarity, dilutions, buffers and more. Every result shows its formula and flags the traps that quietly cost experiments. It runs on your device, so your sequences never leave it.
Protein · molecular weight
= 8,564.84 Da · ε 1,490 M⁻¹cm⁻¹ · pI ~6.6
every result shows its work
Most lab calculators give you a number and hope you typed the right units. Assay shows the working, catches the mistakes, and remembers your reagents.
Paste a sequence or a UniProt ID for MW, extinction coefficient, A₂₈₀ and pI — matched exactly to ExPASy ProtParam. Build tagged constructs and read the expressed MW live.
Every result prints the formula with your numbers substituted in — one tap to your notebook — plus a plain-English “how this is calculated” with references.
Warns before you pipette an impossible volume, blocks impossible dilutions instead of showing a wrong answer, and flags ambiguous sequence bases. Unit slips get caught, not computed.
No account, no login, no ads. Your sequences, reagents and saved constructs stay on your phone. The only optional network call is a public UniProt lookup — when you ask for one.
Save a protein or rotor once and reuse it everywhere — its MW and ε auto-fill your molarity, A₂₈₀ and dilution calcs. No re-keying the same numbers between tools.
A single purchase unlocks Pro — no subscription, no ads, ever. Every calculator that ships next is included.
One-time purchase, yours forever. Unlocks the construct builder, A₂₈₀→concentration, master-mix scaling, multi-component buffer prep, serial-dilution planning, and unlimited saved constructs & rotors reused across every calculator.
The core calculators are free. Correctness is never behind the paywall.