BioPaddles® - Nutrient Agar (NA)

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The BioPaddles® NA/NA can be used for the cultivation of a wide variety of non-fastidious bacteria.

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Nutrient Agar (NA)

The nitrogen, carbon, vitamins, and amino acids in Nutrient Agar are provided by enzymatic digest of gelatin and beef extract. Agar and a proprietary polymer are the solidifying agents.


In the early 1900's, the American Public Health Association (APHA) suggested the formula of Nutrient Agar as a standard culture medium used in water testing. 1 Nutrient Agar continues to be a widely used general purpose medium for growing non-fastidious microorganisms.

If required, enrichments can be added to this medium. Nutrient Agar meets APHA and Association of Official Analytical Chemists (AOAC) standard methods. Nutrient Agar is specified in Standard Methods for the Examination of Water and Wastewater procedures for the examination of food, dairy products, water, and other materials.

BioPaddles® - Nutrient Agar (NA)

Test Factors nonfastidious bacteria
Type of Agar(s) Nutrient Agar
# of Tests 10


Store tightly sealed BioPaddles® in a cool, dry location. Shield from direct sunlight. Store BioPaddles® at room temperature (65 to 77°F/18 to 25°C). Avoid sudden temperature changes. Temperature fluctuations may result in condensation settling at the bottom of the vial. This will not affect the culture properties but could reduce the shelf-life or cause the agar to separate from the plastic paddle support. Do not refrigerate or store at temperatures above 80°F/27°C. Refrigeration may result in water condensation. Avoid freezing.

Refer to Best Before End date (See: BBE stamped on vial). Discard if paddle agar appears oxidized and darker than the expected color or if contaminants appear. The expiration date is based on medium in an intact container that is stored as directed.


DIRECT IMMERSION PROTOCOL for Low Viscosity Liquids: Twist to remove paddle from vial. Do not touch agar surfaces. Fill vial to 40 mL fill line with the liquid to be sampled and immerse paddle or immerse paddle directly in the sample. Both agar surfaces must be completely contacted. Allow at least 15 second contact time (30 seconds is optimal). Remove paddle. Allow liquid to drain off both agar surfaces. Replace paddle in vial and incubate.

SPREAD PROTOCOL for High Viscosity Liquids: Twist to remove paddle from vial. Do not touch agar surfaces. Hold the contact agar surface on a horizontal plane. Deposit the liquid sample as a single drop approximately 1 cm from the handle boundary. Position a sterile glass rod between the handle and the drop of sample. Bring the rod in contact with the drop to create a meniscus. Drag the rod over the agar surface toward the tip of the paddle. Replace paddle in vial and incubate.

SURFACE SAMPLING PROTOCOL (Recovery Rate is about 50%): Twist paddle to remove from vial. Do not touch agar surfaces. Touch the paddle surface (10 cm2) to two different areas of the test surface to cover a total of 20 cm2. Or touch the paddle to the surface once and multiply the colony count by 2. Allow 15 second contact time. Replace the paddle in the vial and Incubate.

AIR SAMPLING PROTOCOL: Twist to remove paddle from vial. Do not touch agar surfaces. Invert paddle and insert the circular cap. Expose for 15 minutes. Replace paddle in vial and incubate.


Incubation of Paddle Growth Incubation Temperature Examine at:
Total Coliform / Bacteria 35 ± 2°C 24 to 48 hours
Total Coliform / Bacteria Room Temperature Up to 5 days
Yeast / Mold 25 to 30°C 48 hours up to 120 hours (5 days)
Yeast / Mold Room Temperature Up to 7 days

Note: Incubation of bacteria after 48 hours may produce confluent growth making enumeration more difficult.


Colony Measuring

Each BioPaddles® paddle has molded media attachment points that are 4mm in length (point-to-point). This feature provides a useful guidepost to estimating nearby colony size.


Twist to remove paddle from vial. Fill vial to 40 mL fill line with 1:9 dilution of household bleach (5.25% sodium hypochlorite). Replace paddle in vial. Allow 15 minute contact time. Remove paddle. Discard bleach solution. Replace paddle in vial and dispose. Alternatively, loosen cap and microwave for 30 seconds, autoclave, or incinerate.

Ship Code: (NH) Non-Hazardous Material - No Fees Applicable

Ship Weight in lbs.: 1