www.tmmedia.in PRODUCT DATA SHEET CHOCOLATE AGAR PLATE TMP 020

INTENDED USE For isolation and cultivation of fastidious microorganisms like Neisseria gonorrhoeae.

COMPOSITION

Ingredients Gms/Ltr Proteose peptone 20.000 Agar 15.000 Sodium chloride 5.000 Disodium phosphate 5.000 Haemoglobin 2.000 Dextrose 0.500

PRODUCT SUMMARY AND EXPLANATION Chocolate agar (CHOC) or chocolate blood agar (CBA), is a nonselective, enriched growth medium used for isolation of pathogenic bacteria. Chocolate agar is used for growing fastidious respiratory bacteria, such as Haemophilus influenzae and Neisseria meningitidis. In addition, some of these bacteria, most notably H. influenzae, need growth factors such as nicotinamide adenine dinucleotide (factor V or NAD) and hemin (factor X), which are inside red blood cells; thus, a prerequisite to growth for these bacteria is the presence of red blood cell lysates. The heat also inactivates enzymes which could otherwise degrade NAD.

PRINCIPLE Medium contains Proteose peptone is a nitrogen source required for the growth of wide variety of organisms. Dextrose acts a carbon energy source. Disodium phosphate buffers the medium whereas sodium chloride maintains the osmotic equilibrium. Agar is the solidifying agent. Heated sheep blood is added to give the medium its “chocolate” appearance. This medium is prepared, stored and dispensed under oxygen-free conditions to prevent the formation of oxidized products prior to use.

INSTRUCTION FOR USE Either streak, inoculate or surface spread the test inoculum aseptically on the plate.

QUALITY CONTROL SPECIFICATIONS Appearance: Chocolate brown colour, opaque gel. Quantity of Medium: 25ml of medium in 90mm plates. pH (at 25°C): 7.3 ± 0.2

Page 1 www.tmmedia.in PRODUCT DATA SHEET INTERPRETATION Cultural characteristics observed after inoculating (103CFU/ml), on incubation at 35 ± 2°C for 48 hours with CO2. Organism ATCC Inoculum Growth (CFU/ml) Neisseria meningitidis 13090 10³ Good Streptococcus pneumoniae 6303 10³ Good Haemophilus influenza 19418 10³ Good

STORAGE AND STABILITY Plated media should be stored at 15-30 °C, media side up, in the unopened or resealed package protected from light. DO NOT FREEZE OR EXPOSE TO HIGH TEMPERATURES. Allow unopened plates to warm to room temperature prior to inoculation. Product which has exceeded the assigned expiration date noted on the label should not be used.

Product Deterioration: Do not use plates that exhibit evidence of drying, cracking, discoloration, microbial contamination or any other signs of deterioration.

REFERENCES

1. Lennette, E.H., Ballows, A., Hausler, W.J.Jr., and Shadomy, H.J. Manual of Clinical Microbiology. 4th ed. Washington D.C.: American society for Microbiology. (1985). 2. N.C.C.L.S. Quality Assurance for Commercially Prepared Microbiological Culture Media. Approved Standard. Vol.10, No.14. NCCLS Document M22-A. (1990). 3. MacFaddin, Jean F., Media for Isolation-Cultivation-Identification-Maintenance of Medical Bacteria. Vol.1. Baltimore, MD.: Williams & Wilkins. (1985). 4. Anderson, Cindy. Great Adventures in the Microbiology Laboratory (7th ed.). Pearson. p. 175. (2013) 5. Gunn B.A (1984). "Chocolate agar: A differential medium for gram positive cocci". Journal of Clinical Microbiology. 20 (4): 822–823.

NOTE: Please consult the Material Safety Data Sheet for information regarding hazards and safe handling practices.

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