Baird Parker Agar Base
CAT No: AS‑1130
Gold‑Standard Selective Medium for Staphylococcus aureus Detection (ISO 6888‑1, FDA‑BAM Compliant)
 
Overview
Baird‑Parker Agar is the internationally recognized gold‑standard selective and diagnostic medium for the isolation and enumeration of coagulase‑positive staphylococci, particularly Staphylococcus aureus, from foods, cosmetics, and clinical specimens.
It is the official reference medium in ISO 6888‑1, FDA‑BAM Chapter 12, USDA protocols, and most national food‑safety standards. The combination of lithium chloride, potassium tellurite, and egg‑yolk emulsion provides extremely high selectivity and clear differentiation of S. aureus colonies.
 
Applications
Detection and enumeration of Staphylococcus aureus in foods (meat, dairy, egg products, ready meals, etc.)
Official method in ISO 6888‑1 (all parts), FDA‑BAM, and USDA food‑safety protocols
Quality control in pharmaceutical and cosmetic microbiology
Confirmation of coagulase‑positive staphylococci in clinical and food samples
 
Key Features & Benefits
Tellurite + lithium chloride → black, shiny colonies of S. aureus
Egg‑yolk emulsion → clear zone (lecithinase activity) + opaque halo (lipase activity)
Glycine + pyruvate → enhanced recovery of injured or stressed cells
Highest specificity and recovery rate among S. aureus selective media
 
Standard Composition (per liter – base only)
Tryptone – 10.0 g
Meat Extract – 5.0 g
Yeast Extract – 1.0 g
Sodium Pyruvate – 10.0 g
Glycine – 12.0 g
Lithium Chloride (LiCl·H₂O) – 5.0 g
Agar – 20.0 g
Final pH: 7.0±0.2 at 25 °C
 
Supplements (added after autoclaving, at 50 °C) (Not Included)
Egg‑Yolk Tellurite Emulsion: 50 mL/L (final potassium tellurite concentration ≈ 0.01%)
Alternatively:
Sterile Egg‑Yolk Emulsion – 50 mL/L
Potassium Tellurite 1% solution – 2.5 mL/L
 
Preparation Instructions
Suspend 58–63 g dehydrated base in 950 mL purified water.
Boil to dissolve completely.
Autoclave at 121 °C for 15 minutes.
Cool to 48–50 °C.
Aseptically add 50 mL sterile Egg‑Yolk Tellurite Emulsion (or separate components).
Mix thoroughly and pour plates (avoid bubbles).
 
Typical Colony Appearance (24–48 h at 35–37 °C)
Staphylococcus aureus: 1.5–3 mm, grey‑black to jet‑black, shiny, with clear zone + opaque halo
Coagulase‑negative staphylococci: small, brown‑black, usually without zones
Other bacteria: completely or almost completely inhibited
 
Storage & Stability
Dehydrated base: Store in a cool, dry place below 30 °C
Prepared plates: Store at 2–8 °C, protected from light; use within 2–3 weeks
 
Intended Use
For laboratory food, cosmetic, and clinical microbiology use only. Not for diagnostic or therapeutic applications without proper validation.