Media Plates

• Routine primary media for aerobes and facultative anaerobes


  • Blood agar, sheep
  • Chocolate agar
  • Columbia colistin nalidixic acid agar [CAN]
  • Phenylethyl alcohol agar (PEA)
  • Streptococcal selective agar (SSA)
  • Eosin methylene blue (EMB)
  • MacConkey agar (MAC)
  • MacConkey sorbitol agar (SMAC)
  • Hektoen enteric agar (HE)
  • Xylose lysine deoxycholate (XLD)
  • Salmonella- Shigella agar (SS)
  • Gram-negative broth (GN)
  • Selenite broth
  • Tetrathionate broth
  • Campylobacter blood agar (Campy BAP)
• Blood agar, sheep


  Enriched medium that will grow most nonfastidious bacteria
• Chocolate agar


  Selective medium for gram-positive microorganisms, supplies X and V factors, incubate in increased CO2
• Columbia colistin nalidixic acid agar [CAN]


  Selective medium for gram-positive cocci and anaerobic gram-negative rods, colistin & nalidixic acid suppress most GN, contain 5% sheep blood
• Phenylethyl alcohol agar (PEA)


  Selective medium for S. pyogenes and S. agalactiae, phenylethyl alcohol inhibits enteric gram-negative rods, contains 5% sheep blood
• Streptococcal selective agar (SSA)


  Selective differential medium for isolation of enteric gram-negative rods, contains trimethoprim-sulfamethoxazole in 5% sheep blood
• Eosin methylene blue (EMB)


  Selective, differential medium for isolation of enteric gram-negative rods, eosin and methylene blue inhibit gram-positives, lactose fermenters are green-black or purple, E. coli produces green metallic sheen, nonlactose-fermenters are colorless
• MacConkey agar (MAC)


  Enriched medium that will grow most nonfastidious bacteria, bile salts and crystal violet inhibit most gram-positives, lactose fermenters are pink, nonlactose-fermenters are colorless
• MacConkey sorbitol agar (SMAC)


  Selective medium for E. coli O157:H7, E. coli O157:H7 does not ferment sorbitol, colonies are colorless, lactose is replaced by sucrose
• Hektoen enteric agar (HE)

  Selective, differential medium for isolation of enteric pathogens from stool, bile salts, bromothymol blue and acid fuchsin inhibit normal GI flora, nonpathogens are orange to salmon pink, non-lactose fermenters are green to blue-green, H2S-positive colonies have black precipitate
• Xylose lysine deoxycholate (XLD)

  Selective, differential medium for isolation of Salmonella and Shigella in stool, deoxycholate inhibits many gram-negative rods and gram-positives, four types of colonies: yellow (E. coli), yellow with black centers (some proteus), colorless or red colonies (Shigella), red colonies with black centers (Salmonella)
• Salmonella- Shigella agar (SS)


  Selective medium for Salmonella and Shigella, brilliant green and bile salts inhibit coliforms, Salmonella and Shigella do not ferment lactose = colonies are colorless, Salmonella produces H2S - black center
• Gram-negative broth (GN)


  Selective enrichment medium for isolation of Salmonella and Shigella from stools and rectal swabs, deoxycholate and citrate salts retard growth of gram-positives, subculture onto selective differential agar after 6-8 hours of incubation
• Selenite broth


  Enrichment broth used for recovery of Salmonella from stool, subculture to enteric media after 8-12 hours of incubation
• Tetrathionate broth


  Enrichment broth for recovery of Salmonella from stool, bile salts and sodium thiosulfate inhibit gram positives and Enterobacteriaceae, inhibits most shigellae, should not be used for recovery of S. typhi, subculture to enteric media after 12-24 hours of incubation
• Campylobacter blood agar (Campy BAP)


  Selective enrichment medium for isolation of Campylobacter from stool, incubate plates in increased CO2 at 42°C, microaerophilic (5% O2)
• Selective media for the isolation of Neisseria gonorrhoeae and Neisseria meningitidis


  • Modified Thayer-Martin (TM)
  • Martin-Lewis
  • New York City medium (NYC)
  • GC-LECT
  • JEMBEC plates
• Modified Thayer-Martin (TM)


  Selective enrichment medium for recovery of Neisseria gonorrhoeae and Neisseria meningitidis from specimens with normal flora, vancomycin, colistin, nystatin, and trimethoprim (inhibit swarming) inhibit growth of other bacteria and fungi, incubate in increased CO2, some N. gonorrhoeae may be inhibited
• Martin-Lewis


  Selective enrichment medium for recovery of N. gonorrhoeae and N. meningitidis from specimens with normal flora, similar to Thayer-Martin, but different antibiotics, inhibits yeast better, incubate in increased CO2
• New York City medium (NYC)


  Selective enrichment medium for isolation of N. gonorrhoeae and N. meningitidis from specimens with normal flora, incubate in increased CO2, some N. gonorrhoeae are inhibited by antibiotics, genital mycoplasmas will grow also
• GC-LECT


  Antibiotics to inhibit GN & GP bacteria & yeast
• JEMBEC plates


  For transportation & growth of N. gonorrhoeae, plates contain Neisseria-selective medium & come with resealable polyethylene bag & CO2-generating tablet, no need to transfer to culture plate
• Plating media for anaerobes


  • Bacteroides bile-esculin agar (BBE)
  • Blood agar, anaerobic, CDC
  • Cycloserine cefoxitin fructose egg yolk agar (CCFA)
  • Cooked meat medium
  • Egg-yolk agar (EYA)
  • Laked kanamycin-vancomycin blood agar (LKV)
  • Phenylethyl alcohol agar (PEA)
  • Thioglycollate broth (THIO)
• Bacteroides bile-esculin agar (BBE)


  Selective differential medium for isolation and identification of Bacteroides fragilis, bile salts and gentamicin act as inhibitors, hydrolysis of esculin indicated by blackening of agar
• Blood agar, anaerobic, CDC


  Enrichment medium for isolation of fastidious anaerobes, contains yeast extract L-cysteine, hemin, and vitamin K, nonselective
• Cycloserine cefoxitin fructose egg yolk agar (CCFA)


  Selective medium for Clostridium difficile
• Cooked meat medium


  For isolation of anaerobes, especially pathogenic Clostridium
• Egg-yolk agar (EYA)


  For determination of lecithinase and lipase production by clostridial and fusobacteria
• Laked kanamycin-vancomycin blood agar (LKV)


  Selective medium for Bacteroides and Prevotella
• Phenylethyl alcohol agar (PEA)


  Inhibits enteric gram-negative rods and swarming by some clostridia
• Thioglycollate broth (THIO)


  All-purpose medium that supports the growth of most aerobes and anaerobes, can be used as a backup broth to detect organisms present in small numbers or anaerobes, thioglycolate acts as a reducing agent, aerobes grow at top, strict anaerobes at bottom, facultative anaerobes throughout, store at room temperature and boil and cool prior to use
• Special bacteriologic media


  • Cystine-tellurite blood agar
  • Loeffler medium
  • Tindale agar
  • Bismuth sulfite agar
  • Cefsulodin-irgasan-novobiocin agar (CIN)
  • Alkaline peptone water
  • Thiosulfate citrate bile salts sucrose agar (TCBS)
  • Rabbit Blood agar
  • Bardet-Gengou
  • Regan Lowe
  • Buffered charcoal yeast extract agar (BCYE)
  • Vaginalis agar (V agar)
  • Human blood Tween agar (HBT)
  • Lowenstein-Jensen
  • Middlebrook 7H10 and 7H11
  • Fletcher medium
• Cystine-tellurite blood agar


  Differential medium for isolation of Corynebacterium diphtheria, C. diphtheriae produces black colonies
• Loeffler medium


  Enrichment medium for recovery and identification of C. diphtheria, promotes development of characteristic granules
• Tindale agar


  Selective differential medium for C. diphtheriae, Corynebacterium spp produce gray to black colonies due to reduction of tellurite, C. diphtheriae colonies are surrounded by a brown halo
• Bismuth sulfite agar


  Selective medium isolation of Salmonella, bismuth sulfite and brilliant green inhibit most others, S. typhi colonies are black, surrounded by metallic sheen, others are light green (some salmonellae may be inhibited)
• Cefsulodin-irgasan-novobiocin agar (CIN)


  Selective medium for Yersinia enterocolitica, Aeromonas, and Plesiomonas shigelloides, crystal violet inhibits most gram-negatives, novobiocin inhibits gram-positive cocci, cefsulodin inhibits most gram-positives and gram-negatives, Y. enterocolitica ferments mannitol and appears as red "bull's-eye" colonies surrounded by colorless halo
• Alkaline peptone water


  Enrichment medium for recovery of Vibrio and Aeromonas from stool, alkaline pH suppresses commensals, subcultured to TCBS
• Thiosulfate citrate bile salts sucrose agar (TCBS)


  Selective for vibrios (differential), high pH inhibits most bacteria, V. cholerae ferments sucrose and produces yellow colonies, V. parahemolyticus and V. vulnificus don't ferment sucrose and usually produce blue-green colonies
• Rabbit Blood agar


  Used to speciate Haemophilus, H. hemolyticus and H. parahemolyticus are hemolytic