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µL
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µL
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Enter values to see results
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µL
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µL
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The Protein Dilution Calculator uses the universal dilution equation (C1V1 = C2V2) to calculate the volumes of protein stock and diluent needed to achieve a desired concentration and volume. Accurate protein dilution is essential for Western blot loading, enzyme assays, ELISA standards, BCA/Bradford assays, and cell treatment experiments. This simple tool eliminates arithmetic errors and ensures consistent protein concentrations across experiments.
The calculation applies the dilution equation:
C1 × V1 = C2 × V2
Solving for V1 (volume of protein stock):
V1 = (C2 × V2) / C1
Diluent Volume = V2 − V1
Where:
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Results
To make 500 µL of 1 mg/mL from a 10 mg/mL stock: mix 50 µL stock with 450 µL buffer (10-fold dilution).
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Results
For 200 µL of 0.1 mg/mL ELISA standard from a 5 mg/mL stock: take 4 µL stock and add 196 µL diluent.
Use a buffer compatible with your downstream application: PBS (phosphate-buffered saline) is common for cell-based assays and ELISAs; Tris-HCl for enzymatic assays; RIPA or lysis buffer for Western blot sample preparation. Avoid diluting into plain water, as the loss of buffering capacity and salt concentration can cause protein denaturation or aggregation. Adding 0.1% BSA to the dilution buffer can reduce non-specific adsorption.
At low concentrations (<0.1 mg/mL), proteins can adsorb to tube walls, causing significant loss. To prevent this: (1) use low-bind tubes (silanized or LoBind); (2) add a carrier protein (0.1–1% BSA) to the diluent; (3) add a small amount of detergent (0.01–0.05% Tween-20); (4) avoid repeated freeze-thaw cycles of diluted protein; (5) prepare dilutions fresh when possible.
If C2 > C1, dilution is not possible — you need to concentrate. Common methods include: (1) ultrafiltration using Amicon centrifugal concentrators (choose MWCO well below your protein size); (2) lyophilization (freeze-drying) followed by reconstitution in less volume; (3) precipitation with ammonium sulfate or TCA followed by resuspension; (4) dialysis against a hygroscopic polymer like PEG.
Roboculator Team
The Roboculator Team explains calculations, planning tools, and practical formulas in clear language for real-life situations.
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