Know your culture – a quick reference guide

Society for Applied Microbiology

Javeed Kakroo

Culture is a technique where we grow microorganisms in a nutritional liquid or on a solid medium in order to increase numbers and simplify identification. It is also important as a first step in several laboratory techniques and for testing of antimicrobial sensitivity.

There are many types of medium available for culturing microorganisms, and so it is important to know which is best to use – especially for organisms that are difficult to grow.

culture-table2

Many of these media are available commercially, but for some it can be more cost effective to prepare the media yourself. For completeness, recipes for all media above are listed in alphabetical order. Adjustment of these recipes may be necessary for some cultures, but these will provide a good starting point. Most of the recipes include ‘agar’, which can be left out to make liquid cultures, but some rely on the use of nutrient agars which will require replacing with another nutrient source to make a liquid medium for culture.

Contents:

Bacteroides bile-esculin (with gentamicin and bile) agar
Bordet-Gengou agar with methicillin or cephalexin
Buffered Charcoal Yeast Extract agar
Campylobacter-selective agar
Cefsulodin-Irgasan-Novobiocin agar
Cystine Heart agar
Cystine-Tellurite Blood agar
Fletcher’s medium with rabbit serum
Gram-Negative Enrichment Broth
Hektoen agar
Horse Blood-Charcoal agar
Kanamycin-Vancomycin Laked Blood agar
Leptospira Medium with Bovine Serum Albumin (BSA)-Tween 80
Löffler’s Coagulated Serum Medium
MacConkey agar
MacConkey-Sorbitol agar
Modified Thayer-Martin agar
New York City agar
Pseudomonas cepacia agar
Regan-Lowe Cephalixin agar
SalmonellaShigella agar
Selenite Enrichment Broth
Stuart Medium with rabbit serum
Thiosulfate-Citrate-Bile Salts-Sucrose agar
Tinsdale agar
Xylose-Lysine-Deoxycholate agar

 

bacteroides-bile-esculin

Bacteroides bile-esculin with gentamycin and bile

 

Bacteroides bile-esculin (with gentamicin and bile) agar:

45g/l Tryptic Soy Agar
20g/l Ox bile
1 g/l Esculin
5g/l Ferric Ammonium Citrate
12mg/l Hemin
100mg/l Gentamicin

Bordet-Gengou agar with methicillin or cephalexin:

15g/l Agar
5g/l Potato Infusion
5g/l Sodium Chloride
3g/l Meat Peptone
2g/l Casein Peptone
10ml/l Glycerol
15% Sheep’s blood
Methicillin or Cephalexin as appropriate to your sample

 

bordetella-pertussis-charcoal-agar-plate-cropped

Buffered Charcoal Yeast Extract Agar

 

Buffered Charcoal Yeast Extract agar:

17g/l Agar
5g/l Yeast Extract
10g/l ACES Buffer
3g/l Activated Charcoal
5g/l Potassium Hydroxide
1g/l alpha-Ketoglutarate
4g/l L-Cysteine
25g/l Ferric Pyrophosphate

Campylobacter-selective agar (for example):

5g/l Agar
12g/l Pancreatic Digest of Casein
5g/l Peptic Digest of Animal Tissue
5g/l Sodium Chloride
4g/l Activated Charcoal
3g/ Yeast Extract
3g/l Beef Extract
1 g/l Corn Starch
1g/l Cycloheximide
32mg/l Hemin
32mg/l Cefoperazone
20mg/l Vancomycin

 

cin_agar_800x600

Cefsulodin-Irgasan-Novobiocin agar

 

Cefsulodin-Irgasan-Novobiocin agar:

20g/l Mannitol
17g/l Peptone
5g/l Agar
3g/l Proteose Peptone
2g/l Yeast Extract
2g/l Sodium Pyruvate
1g/l Sodium Chloride
5g/l Sodium Deoxycholate
5g/l Sodium Cholate
30mg/l Neutral Red
10mg/l Magnesium Sulfate
4mg/l Irgasan®
4mg/l Cefsulodin
5mg/l Novobiocin
1mg/l Crystal Violet

Cystine Heart agar:

15g/l Agar
10g/l Beef Heart (Infusion from 500g)
10g/l Proteose Peptone
10g/l Dextrose
5g/l Sodium Chloride
1g/l L-Cystine

 

gram-ve-bacilli-blood-agar

Cystine-Tellurite Blood agar

 

Cystine-Tellurite Blood agar:

15g/l Agar
13g/l Casein Peptone
5g/l Sodium Chloride
5g/l Yeast Extract
2g/l Beef Heart (Infusion from 500g)
44mg/l L-Cystine
50ml/l 1% Potassium Tellurite
5% Sheep’s Blood

Fletcher’s medium with rabbit serum:

5g/l Agar
5g/l Sodium Chloride
3g/l Peptone
2g/l Beef Extract
80ml/l Rabbit Serum

Gram-Negative Enrichment Broth:

10g/l Pancreatic Digest of Casein
10g/l Peptic Digest of Animal Tissue
5g/l Sodium Chloride
5g/l Sodium Citrate
4g/l Dipotassium Phosphate
2g/l Mannitol
5g/l Monopotassium Phosphate
1g/l Dextrose
5g/l Sodium Deoxycholate

 

hektoen-agar-cropped

Hektoen agar

 

Hektoen agar:

5g/l Agar
12g/l Peptic Digest of Animal Tissue
12g/l Lactose
12g/l Sucrose
9g/l Bile Salts
5g/l Sodium Chloride
5g/l Sodium Thiosulfate
3g/l Yeast Extract
2g/l Salicin
5g/l Ferric Ammonium Citrate
1g/l Acid Fuchsin
64mg/l Bromothymol Blue

Horse Blood-Charcoal agar:

12g/l Agar
10g/l Beef Extract
10g/l Casein/Meat polypeptone
10g/l Starch
5g/l Sodium Chloride
4g/l Charcoal
1mg/l Nicotinic acid
10% Horse Blood

Kanamycin-Vancomycin Laked Blood agar:

20g/l Peptamin
17g/l Agar
5g/l Sodium Chloride
2g/l Yeast Extract
1g/l Dextrose
1g/l Sodium Bisulfite
5mg/l Hemin
1mg/l Vitamin K
40ml/l Vancomycin
40ml/l Kanamycin
50ml Laked Sheep’s Blood

Leptospira Medium with Bovine Serum Albumin (BSA)-Tween 80:

Base medium (900ml)11g/l Agar

1g/l Disodium Phosphate
1g/l Sodium Chloride
3g/l Monopotassium Phosphate
1ml/l 10% Glycerol
1ml/l 25% Ammonium Chloride solution
1ml/l 10% Sodium Pyruvate solution
1ml/l 0.5% Thiamine solution

Albumin Supplement (100ml)Magnesium Chloride-Calcium Chloride solution:100g/l BSA

125ml/l 10% Tween-80 solution
100ml/l 0.5% Iron Sulfate solution
10ml/l Magnesium Chloride-Calcium Chloride solution (see below)
10ml/l 0.02% Cyanocobalamin solution
10ml/l 0.4% Zinc Sulfate solution

Magnesium Chloride-Calcium Chloride solution:

15g/l Calcium Chloride Dihydrate
15g/l Magnesium Chloride Hexahydrate

 

loefflers-coagulated-serum-medium

Loeffler’s Coagulated Serum Medium

 

Löffler’s (also spelled ‘Loeffler’) Coagulated Serum Medium:

5g/l Dextrose
5g/l Gelatin Peptone
5g/l Beef Extract
25g/l Sodium Chloride
750ml/l Bovine Serum

 

macconkey_agar_with_lf_and_lf_colonies

MacConkey agar

 

MacConkey agar:

17g/l Peptone
5g/l Agar
10g/l Lactose
5g/l Sodium Chloride
5g/l Bile Salts
30mg/l Neutral Red
1mg/l Crystal Violet

MacConkey-Sorbitol agar:

As above, but including 10g/l sorbitol instead of lactose

Modified Thayer-Martin agar:

23g/l Peptic Digest of Animal Tissue
20g/l Agar
5g/l Sodium Chloride
5g/l Dextrose
1g/l Starch
200ml/l Lysed Blood
5mg/l Colistin Methane Sulphate
3mg/l Vancomycin

New York City agar:

20g/l Agar
15g/l Proteose Peptone
5g/l Glucose
5g/l Sodium Chloride
4g/l Dipotassium Hydrogen Phosphate
1g/l Corn Starch
1g/l Potassium Dihydrogen Phosphate
100ml/l Horse Blood Cells
60ml/l Horse Plasma
Yeast Autolysate Supplement (Available commercially, recipe below)

10g/l Yeast Autolysate fractions
1g/l Glucose
15g/l Sodium Bicarbonate

NYC Supplement, also known as C.L.A.T. antibiotics (available commercially, recipe below)

5mg/l Colustin Methane Sulphonate

4mg/l Linomycin

1mg/l Amphotericin B

5mg/l Trimethoprim Lactate

Pseudomonas cepacia agar:

15g/l Agar
5g/l Sodium Pyruvate
3g/l Dipotassium Phosphate
1g/l Monopotassium Phosphate
5g/l Bile Extract
1g/l Enzymatic Digest of Animal Tissue
1g/l Ammonium Sulfate
2g/l Magnesium Sulfate
1g/l Ticarcillin
20mg/l Phenol Red
10mg/l Ferrous Ammonium Sulphate
1mg/l Crystal Violet
300 000Units Polymyxin B

Regan-Lowe Cephalixin agar:

As Horse Blood-Charcoal Agar with the inclusion of 40mg/l Cephalexin

 

salmonella-shigella-agar

SalmonellaShigella agar

 

SalmonellaShigella agar:

5g/l Agar
10g/l Lactose
5g/l Bile Salts
5g/l Sodium Citrate
5g/l Sodium Thiosulfate
5g/l Beef Extract
5g/l Enzymatic Digest of Casein
5g/l Enzymatic Digest of Animal Tissue
1g/l Ferric Citrate
25mg/l Neutral Red
33mg/l Brilliant Green

Selenite Enrichment Broth:

10g/l Sodium Phosphate
5g/l Pancreatic Digest of Casein
4g/l Lactose
4g/l Sodium Selenite

Stuart Medium with rabbit serum:

10g/l Sodium Glycerophosphate
3g/l Agar
1g/l Sodium Thioglycollate
1g/l Calcium Chloride
2mg/l Methylene Blue
80ml/l Rabbit Serum

 

thiosulfate-citrate-bile-salts-sucrose-agar

Thiosulfate-Citrate-Bile salts-Sucrose agar

 

Thiosulfate-Citrate-Bile Salts-Sucrose agar:

20g/l Sucrose
15g/l Agar
10g/l Dipeptone
10g/l Sodium Citrate
10g/l Sodium Thiosulfate
10g/l Sodium Chloride
5g/l Yeast Extract
5g/l Ox Bile
3g/l Sodium Cholate
1g/l Ferric Citrate
40mg/l Bromothymol Blue
40mg/l Thymol Blue

Tinsdale agar:

20g/l Protease Peptone
15g/l Agar
5g/l Yeast Extract
5g/l Sodium Chloride
425g/l Sodium Thiosulfate
3445g/l Potassium Tellurite
24g/l L-Cystine
100ml Serum

 

xldsalmonella

Xylose-Lysine-Deoxycholate agar

 

Xylose-Lysine-Deoxycholate agar:

5g/l Agar
5g/l Lactose
5g/l Sucrose
8g/l Sodium Thiosulfate
5g/l L-Lysine HCl
5g/l Sodium Chloride
3g/l Yeast Extract
1g/l Sodium Deoxycholate
8g/l Ferric Ammonium Citrate
80mg/l Phenol Red

 

Robert Millar (University of Warwick)

Society for Applied Microbiology