Technical Data
Columbia CNA Agar (Powder)
Microbiological Grade
Storage RT/4C    Shipping RT
Components shown as g/liter
Corn Starch1.0
Nalidixic Acid0.010
Sodium Chloride5.0
Yeast Enriched Peptone10.0
Peptic Digest of Animal Tissue8.0
Casein Digest Peptone5.0
A selective medium for isolation of gram positive bacteria. Most often utilized with blood added. Eliner, et al. added colistin and nalidixic acid to Columbia Agar to suppress the growth of Gram negative bacteria. The addition of 5-10% sheep red blood cells to the base demonstrates hemolytic patterns of the Staphylococci and Streptococci.

Directions per Liter: Dissolve 43 grams in 800-900ml of ddH2O stirring gently with heating until completely solubilized. Adjust pH of the medium to the desired level. Add additional water to bring the solution to 1L. Dispense into appropriate containers, loosen caps and autoclave for 15 minutes at 121C (15psi). Prepare 5-10% blood agar by adding the appropriate volume of sterile defibrinated blood to melted sterile agar medium, cooled to 45-50C. Dispense into Petri dishes or tubes

Storage and Stability: Store powdered media at RT. Opened bottles should be capped tightly and kept in a dark, low humidity environment. Prepared media should be kept at 4C and used within a short period of time.

Appearance: Light beige, homogeneous, free flowing powder

Solubility: Yellow, clear, complete after autoclaving

pH: As Reported

Important Note: This product as supplied is intended for research use only, not for use in human, therapeutic or diagnostic applications without the expressed written authorization of United States Biological.