Absorbance at 280 nm to milligrams per milliliter
Type a value in A280 to get it in mg/mL instantly.
1mg/mL
That's about the same as a working solution. A 20 µL sample at that concentration holds about 20 µg of protein.
Convert the other way: mg/mL to A280
What it means
How much protein is that?
A280 assumes a 1 cm path length and a protein with ordinary aromatic content. Nucleic acid contamination absorbs at 280 too and inflates the reading.
The math
How to convert A280 to mg/mL
Beer–Lambert, rearranged: mg/mL = A280 ÷ extinction coefficient, for a 1 cm path. The figures below use the protein selected above.
Example: 1 A280 = 1 mg/mL.
The table below is for Unknown protein (A280 = 1.0 per mg/mL).
Every unit
Your concentration in every unit
Tables
A280 to mg/mL conversion table
| A280 | mg/mL |
|---|---|
| 0.01 A280 | 0.01 mg/mL |
| 0.05 A280 | 0.05 mg/mL |
| 0.1 A280 | 0.1 mg/mL |
| 0.25 A280 | 0.25 mg/mL |
| 0.5 A280 | 0.5 mg/mL |
| 1 A280 | 1 mg/mL |
| 2 A280 | 2 mg/mL |
| 5 A280 | 5 mg/mL |
| 10 A280 | 10 mg/mL |
| 20 A280 | 20 mg/mL |
| 50 A280 | 50 mg/mL |
mg/mL to A280 conversion table
| mg/mL | A280 |
|---|---|
| 0.01 mg/mL | 0.01 A280 |
| 0.05 mg/mL | 0.05 A280 |
| 0.1 mg/mL | 0.1 A280 |
| 0.25 mg/mL | 0.25 A280 |
| 0.5 mg/mL | 0.5 A280 |
| 1 mg/mL | 1 A280 |
| 2 mg/mL | 2 A280 |
| 5 mg/mL | 5 A280 |
| 10 mg/mL | 10 A280 |
| 20 mg/mL | 20 A280 |
| 50 mg/mL | 50 A280 |
Quick answers
Quick answers
- How many mg/mL is 1 A280?
- 1 A280 is 1 mg/mL.
- How many mg/mL is 10 A280?
- 10 A280 is 10 mg/mL.
The units
About these units
Absorbance at 280 nm (A280)
What the spectrophotometer reads, in a 1 cm cuvette.
Milligrams per milliliter (mg/mL)
The standard working unit for protein solutions.
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