Ampicillin (Amp) Stock Preparation
Updated 6/29/2015 05:25 PM
Introduction
Materials
- Consumables
- ampicillin (sodium salt or trihydrate)
- 1N NaOH
- ethyl alcohol
- Disposables
- light-tight sealed PP container
- weigh dishes/paper
- Equipment
- balance
Procedure
Dilution in Selective Media
Table5
A A | B B | |
1 1 | Media Volume (ml)* | 1000 |
2 2 | Desired Ampicillin Media Concentration (μg/ml)* | 100 |
3 3 | Ampicillin Stock Volume (μl) | 2000 |
Set the Media Volume, Desired Media Concentration, and Final Concentration (below) parameters to return the proper volume of antibiotic stock to add to the media.
Component Composition
Table1
A A | B B | |
1 1 | Final Volume (ml)* | 10 |
2 2 | Final Concentration (mg/ml)* | 50 |
Table2
A A | B B | C C | |
1 1 | Component | Amount | Unit |
2 2 | Ampicillin trihydrate | 577.3303568873 | mg |
3 3 | 1N NaOH | 1.5 | ml |
4 4 | ethyl alcohol | 7 | ml |
5 5 | dH2O | to final volume |
Table3
A A | B B | C C | |
1 1 | Component | Amount | Unit |
2 2 | Ampicillin sodium salt | 531.4530208065 | mg |
3 3 | ethyl alcohol | 7 | ml |
4 4 | dH2O | to final volume |
Preparation
- Add components in the order listed above to a light-tight PP container.
CRITICALBe sure to add the NaOH to the Ampicillin trihydrate stock to solubilize, otherwise it will not fully dissolve.
- Once solution is fully dissolved, store at -20°C.
There is no need to filter sterilize this solution since it is 70% ethyl alcohol.
This protocol describes the preparation of an Ampicillin stock solution. The concentration of this stock solution is based on the weight of anhydrous Ampicillin.
Note: Typical stock solutions for this antibiotic in selectable media are made at 50mg ml-1 and are used at a final concentration of 20-40 μg ml-1 for stringent plasmids and 100 μg ml-1 for relased plasmids. .
Note: The preparation in ethanol allows the solution to be stored at -20°C without degrading through successive freeze-thaw cycles.
Note: Selective solid medium prepared with this stock solution has proven selective even after 1 year of storage.