LB

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== Summary ==
== Summary ==
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L-Broth or LB Medium.  Standard growth medium for a variety of bacteria and conditions.
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Luria-Bertani Medium (aka L-Broth or LB Medium)(Bertani says LB really stands for lysogeny broth.) LB is a standard growth medium for a variety of bacteria and conditions.
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== Ingredients ==
== Ingredients ==
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#10 g Bacto-tryptone
#10 g Bacto-tryptone
#5 g yeast extract
#5 g yeast extract
#10 g NaCl
#10 g NaCl
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#distilled water
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For plates also add
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#15g agar
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See also: [[Silver: LB Liquid]]
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''Note:'' There are two formulations of LB, Miller and Lennox, that differ in the amount of NaCl. Lennox has less salt, only 5 g/L. The Qiagen miniprep kit recommends LB with 10 g NaCl for highest plasmid yields.
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==Protocol==
==Protocol==
#Mix dry ingredients and add distilled water up to 1 Liter
#Mix dry ingredients and add distilled water up to 1 Liter
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#Autoclave (liquid cycle)
#Autoclave (liquid cycle)
#* 250°'''F''', 22psi, 30 minutes
#* 250°'''F''', 22psi, 30 minutes
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 +
Notes: We do not pH medium when we make it on the fly.  However, if it is really important, pH the medium to 7.0 with 5M NaOH (~200µL). Check with pH paper
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 +
===For plates===
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#Mix dry ingredients and add distilled water up to less than 1 Liter
 +
#After dissolved, add agar
 +
#Pour into 2 L flask (or greater)
 +
#Autoclave (liquid cycle)
 +
#* 250°'''F''', 22psi, 30 minutes
 +
#Cool media down to 60-55C (uncomfortable but not painful)
 +
#Add appropriate antibiotic
 +
#Pour the solution on sterile (???) plates
 +
#Let solidify about 1 h, wrap, label (name, date, additive)
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#keep at 4°C
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==Source==
==Source==
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J. Sambrook, D.W. Russell, ''Molecular Cloning: A Laboratory Manual'' (Cold Spring Harbor Laboratory Press, New York, ed. 3, 2001)
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Adapted From:
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J. Sambrook, D.W. Russell, ''Molecular Cloning: A Laboratory Manual'' (Cold Spring Harbor Laboratory Press, New York, ed. 3, 2001) pg. A2.2
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 +
[[Category:Material]]  [[Category:Standard Media]]

Current revision

Contents

Summary

Luria-Bertani Medium (aka L-Broth or LB Medium). (Bertani says LB really stands for lysogeny broth.) LB is a standard growth medium for a variety of bacteria and conditions.

Ingredients

  1. 10 g Bacto-tryptone
  2. 5 g yeast extract
  3. 10 g NaCl

For plates also add

  1. 15g agar

See also: Silver: LB Liquid

Note: There are two formulations of LB, Miller and Lennox, that differ in the amount of NaCl. Lennox has less salt, only 5 g/L. The Qiagen miniprep kit recommends LB with 10 g NaCl for highest plasmid yields.

Protocol

  1. Mix dry ingredients and add distilled water up to 1 Liter
  2. Pour into 2 L flask (or greater)
  3. Autoclave (liquid cycle)
    • 250°F, 22psi, 30 minutes

Notes: We do not pH medium when we make it on the fly. However, if it is really important, pH the medium to 7.0 with 5M NaOH (~200µL). Check with pH paper

For plates

  1. Mix dry ingredients and add distilled water up to less than 1 Liter
  2. After dissolved, add agar
  3. Pour into 2 L flask (or greater)
  4. Autoclave (liquid cycle)
    • 250°F, 22psi, 30 minutes
  5. Cool media down to 60-55C (uncomfortable but not painful)
  6. Add appropriate antibiotic
  7. Pour the solution on sterile (???) plates
  8. Let solidify about 1 h, wrap, label (name, date, additive)
  9. keep at 4°C

Source

Adapted From:

J. Sambrook, D.W. Russell, Molecular Cloning: A Laboratory Manual (Cold Spring Harbor Laboratory Press, New York, ed. 3, 2001) pg. A2.2

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