(AB) Phenylethanol Agar, 500 grams

Phenylethanol when incorporated into a nutrient medium was found to inhibit gram-negative microorganisms while allowing the growth of gram-positive microorganisms found in clinical specimens. Blood plates may be prepared using this medium but cannot be used for determining hemolytic patterns. Phenylethanol Agar is a selective agar medium used for the isolation of staphylococci and streptococci. (Alpha Biosciences # P16-107-500gm)

Use: Phenylethanol Agar is a selective agar medium used for the isolation of staphylococci and streptococci.

Description: Phenylethanol when incorporated into a nutrient medium was found to inhibit gram-negative microorganisms while allowing the growth of gram-positive microorganisms found in clinical specimens. Blood plates may be prepared using this medium but cannot be used for determining hemolytic patterns.

Formula* per Liter:

• Casein Digest Peptone ................ 15.0g
• Papaic Digest of Soybeans ......... 5.0g
• Phenylethanol ................................... 2.5g
• Sodium Chloride ........................... 5.0g
• Agar .................................................15.0g

Final pH: 7.3 ± 0.2 at 25.0°C

* Grams per liter may be adj. or formula supplemented to obtain desired performance

Preparation: Mix 42.5 grams of the medium in a Liter of purified water until evenly dispersed. Heat with repeated stirring and boil for one minute to dissolve completely. Distribute and autoclave at 121°C for 15 minutes. The medium may be used with or without blood. Prepare 5 to 10% blood agar by adding the appropriate volume of sterile defibrinated blood to melted sterile agar medium, cooled to 45-50°C. Dispense into Petri dishes or tubes.

Quality Control Specifications:

1. The powder is homogeneous, free flowing and light beige.
2. Visually the prepared medium is clear to slightly hazy and pale yellow.
3. Expected cultural response after 18-24 hours at 35.0°C.

Organism                                                      Plain                              5% Sheep Blood

Proteus mirabilis ATCC 12453                    Inhibited                                 Inhibited

Staphylococcus aureus ATCC 25923          Growth                                   Growth

Streptococcus pneumonia ATCC 6305        Growth                                   Growth

Streptococcus pyogenes ATCC 19615        Growth                                   Growth

Storage: Store the sealed bottle containing the dehydrated medium at 2 to 30.0°C. Once opened and recapped, place the container in a low humidity environment at the same storage temperature. Protect it from moisture and light. The dehydrated medium should be discarded if it is not free flowing or if the color has changed from the original light beige color.