Spectrophotometry
Protein extinction coefficient (A280)
Sequence to ε280, MW, and E0.1%, the Pace way. Feeds the A280 calculator.
ε280 = nW·5500 + nY·1490 + nSS·125
One-letter codes (case and whitespace ignored). Non-standard letters are excluded with a note, never guessed.
Oxidized adds 125 M⁻¹cm⁻¹ per disulfide (Pace).
Protocol result
⚗ Aliquot
Protein extinction coefficient (A280) · ε280 = nW·5500 + nY·1490 + nSS·125 · the lab bench, calculated
Protein A280✓ ε280 = nW·5500 + nY·1490 + nSS·125
ε₂₈₀ = 20970 M⁻¹cm⁻¹.
1
A 1 g/L solution reads 7.386 at 280 nm (E0.1%).
ε280
20970 M⁻¹cm⁻¹
MW
2839 g/mol
E0.1% (1 g/L)
7.386
Residues
22
Trp / Tyr / Cys
3 / 3 / 0