Cat. no. K31 FB Broth, 16x125mm Tube, 10ml 20 tubes/box
Cat. no. R75BX FB Broth, 13x85mm Tube, 4ml 100 tubes/box


Hardy Diagnostics FB (Fastidious Bacteria) Broth is used for the enrichment and cultivation of Neisseria spp., Haemophilus spp., Streptococcus spp., Corynebacterium spp. and other fastidious bacteria from clinical specimens.


Utilization of an enrichment broth for improved sensitivity of cultures is recommended in the majority of clinical microbiology texts, because these specimens may contain small numbers of microorganisms.(1) A study by Cartwright et al. showed the relative efficacy of two commercially available enrichment broths compared to enrichment in FB Broth. FB Broth supported the growth of a number of organisms that were not recoverable in enriched Eugon Broth or supplemented Thioglycollate Broth, including Neisseria meningitidis, Haemophilus influenzae, Corynebacterium jeikeium and Streptococcus pneumoniae, as well as several species implicated in acute and chronic meningitis. FB Broth provided earlier visual detection of positive cultures from specimens with relatively low numbers of bacteria than other formulas commercially available.(5)


Ingredients per liter of deionized water:*

Pancreatic Digest of Casein 12.0gm
Yeast Extract 8.0gm
Dextrose 7.5gm
Peptic Digest of Animal Tissue 6.0gm
Sodium Chloride 5.0gm
Brain Heart Infusion 3.0gm
TRIS 3.7gm
Pancreatic Digest of Gelatin 1.0gm
Agarose 750.0mg
L-Cysteine HCl 100.0mg
Magnesium Sulfate 100.0mg
Ferrous Sulfate 20.0mg
Hematin 15.0mg
NAD 15.0mg
Pyridoxal 6.0mg
Tween® 80 0.5ml

Final pH 7.0 +/- 0.2 at 25ºC.

* Adjusted and/or supplemented as required to meet performance criteria.


Storage: Upon receipt store at 2-8ºC. away from direct light. Media should not be used if there are any signs of deterioration, discoloration, contamination, or if the expiration date has passed. Product is light and temperature sensitive; protect from light, excessive heat, moisture, and freezing.



Specimen Collection: Transport all specimens to the laboratory immediately. CSF specimens must be collected in sterile screw cap containers. Do not refrigerate unless viral studies are requested. Consult listed references for information regarding collection and transport of specimens.(1,2,4)

Method of Use:

Consult listed references for processing of additional specimens.(1,2,4)

Cerebral Spinal Fluid (CSF):

Use appropriate biohazard precautions. It is recommended that a biological safety cabinet be used when processing CSF specimens.

1. Centrifuge the specimen if greater than 1ml for 20 minutes at 1500-3000xg. Allow the centrifuge to stop. Do not brake . If there is 1ml of specimen or less, vortex.

2. Aspirate the supernatant with a sterile pipet leaving 0.5 to 1.0ml of fluid in the specimen tube. Retain the supernatant for additional studies.

3. Vortex the sediment vigorously for at least 30 seconds to resuspend the pellet. This step is critical. Do not use a pipet to mix the sediment because the bacteria cells may adhere to the sides of the tube and cause false-negative findings.

4. Using a sterile pipet, inoculate the media by placing 1 or 2 drops of the vortexed sediment into the broth and prepare slides for staining.

5. Incubate the broth media aerobically at 35ºC.


Observe broth daily for 5-7 days for turbidity. Any visible signs of growth or turbidity indicates a positive culture.

Consult listed references for identification of isolated organisms.(1,2,4)


FB Broth is a non-selective media; subculture to plated media, as well as additional biochemical and/or serological tests, may be required for complete identification.

FB Broth is not recommended for the recovery of extremely fastidious organisms such as Helicobacter pylori, Legionella pneumophil or Bartonella (Rochalimaea) henselae. Consult listed references for information regarding cultivation of extremely fastidious organisms.(1,2)

Some organisms, including Neisseria gonorrhoeae, may take up to 5-7 days for visible growth to appear.


Standard microbiological supplies and equipment such as loops, other culture media, swabs, applicator sticks, biological safety cabinet, incinerators, and incubators, etc., as well as serological and biochemical reagents, are not provided.


Test Organisms Inoculation Method* Incubation Results
Time Temperature Atmosphere
Streptococcus pneumoniae
ATCC® 6305
A 24-48hr 35°C Aerobic Growth
Neisseria meningitidis
ATCC® 13090
A 24-48hr 35°C Aerobic Growth
Haemophilus influenzae
ATCC® 10211
A 24-48hr 35°C Aerobic Growth
Corynbacterium jeikeium
ATCC® 43734
A 24-48hr 35°C Aerobic Growth

User Quality Control


FB Broth should appear clear, medium amber in color, and may have a slight dark precipitate.


1. Versalovic, J., et al. Manual of Clinical Microbiology. American Society for Microbiology, Washington, D.C.

2. Tille, P.M., et al. Bailey and Scott's Diagnostic Microbiology, C.V. Mosby Company, St. Louis, MO.

3. Anderson, N.L., et al. Cumitech 3B; Quality Systems in the Clinical Microbiology Laboratory, Coordinating ed., A.S. Weissfeld. American Society for Microbiology, Washington, D.C.

4. Isenberg, H.D. Clinical Microbiology Procedures Handbook, Vol. I, II & III. American Society for Microbiology, Washington, D.C.

5. Cartwright, C.P. and F. Stock, et al. 1994. Improved enrichment broth for cultivation of fastidious organisms. J. Clin. Microbiol. ; 32: 1825-1826.

ATCC is a registered trademark of the American Type Culture Collection.
Tween is a registered trademark of ICI Americas, Inc.