⚠️ Research Use Only. Not validated for clinical diagnostic use. Always verify calculations against manufacturer's datasheet.

Antibiotic Stock Solution Calculator

Calculate powder mass, solvent volume, dilution factor, and step-by-step preparation protocol for 30+ antibiotics — with salt factor correction, solubility check, stability estimate, and multi-antibiotic cocktail planning.

30+ Antibiotics Salt Factor Correction Solubility Check Stability Estimate Cocktail Planner Vial Reconstitution

Antibiotic Stock Preparation

Select Antibiotic Preset

Stock Concentration (mg/mL)

Stock Volume to Prepare (mL)

Working Concentration (µg/mL)

Media Volume (mL)

Purity (%)

Cost per mg ($, optional)

Account for powder volume displacement Generate step-by-step protocol

Results

Mass to Weigh

—mg

Provenance: Dataset v— · —

Solvent Volume

—

Dilution Factor

—

Stock to Add

—

Diluent to Add

—

Final Conc. Range

—

Stock Cost

—

Multi-Antibiotic Cocktail Planner

Prepare media with 2 or more antibiotics simultaneously. Select antibiotics and enter the total media volume.

Media Volume (mL)

Select Antibiotics (2–3)

Lyophilized Vial Reconstitution

Calculate how much diluent to add to a lyophilized antibiotic vial to achieve a target concentration.

Powder Mass in Vial (mg)

Purity (%)

Target Concentration (mg/mL)

Target Volume (mL, optional)

Diluent Volume to Add

—mL

Active Mass

—

Final Concentration

—

Final Volume

—

Dilution Calculator (C₁V₁ = C₂V₂)

Solve for any variable in the dilution equation. Leave one field blank to solve for it.

C₁ Stock Concentration

V₁ Stock Volume

C₂ Final Concentration

V₂ Final Volume

Solved Value

—

C₁ Stock

—

V₁ Stock Vol

—

C₂ Final

—

V₂ Final Vol

—

Dilution Factor

—

Diluent to Add

—

Resistance Gene → Antibiotic Mapper

Select a resistance gene from your plasmid/strain to get the recommended antibiotic, concentration, and solvent. Simulating a construct first? Molecular Cloning Simulator → then come back here to plan your selection prep.

How to Use This Calculator

1. Select or Enter Parameters

Choose from 30+ antibiotic presets or enter custom stock/working concentrations, volumes, and purity.

2. Review Corrections

Salt factor, solubility limit, volume displacement, and stability are automatically checked and flagged.

3. Follow the Protocol

Copy or print the step-by-step protocol for your lab notebook. Includes weighing, solvent, and dilution steps.

Frequently Asked Questions

How do I calculate antibiotic stock solution mass?

Multiply stock concentration (mg/mL) × stock volume (mL) = base mass (mg). Then multiply by the salt factor for the specific salt form, and divide by purity percentage. Example: 10 mg/mL × 10 mL × 1.09 (ampicillin sodium) ÷ 1.0 = 109 mg.

What is a salt factor?

Salt factor converts the mass of the active antibiotic base to the mass of the salt form. For example, ampicillin sodium has a salt factor of 1.09, meaning you need 9% more mass than the base form. Each antibiotic preset includes its specific salt factor.

Why does solubility matter?

Each antibiotic has a solubility limit in its recommended solvent. If your target stock concentration exceeds this limit, the powder will not fully dissolve. The calculator warns you when this happens and suggests reducing the stock concentration or using a different solvent.

How do I prepare a multi-antibiotic cocktail?

Use the Cocktail Planner tab. Select 2-3 antibiotics, enter the media volume, and the calculator returns the exact volume of each stock to add to the same media. Always verify compatibility between antibiotics before preparing cocktails.

How do I reconstitute a lyophilized vial?

Use the Vial Reconstitution tab. Enter the powder mass, purity, and target concentration. The calculator returns the exact diluent volume to add. Always check the manufacturer's datasheet for recommended diluent and stability.

What is volume displacement correction?

When you dissolve powder in a solvent, the powder itself occupies volume. For example, 1 g of powder displaces approximately 0.7 mL. The calculator subtracts this from the total solvent volume to ensure the final concentration is accurate.

How is stability estimated?

The calculator uses first-order degradation kinetics. Given a storage temperature and degradation rate, it estimates the shelf-life (time to reach a target potency, typically 90%). Actual stability depends on the specific antibiotic and storage conditions.

Can I use this for clinical dosing?

No. This tool is for research laboratory use only. Clinical dosing requires pharmacokinetic calculations, patient-specific parameters, and professional oversight. Always consult the manufacturer's datasheet and institutional guidelines.

Related Resources

Pharma Calculators Biostatistics Molecular Docking All Topics