LB Agar (Miller), a nutritionally rich medium designed for growth of pure cultures of recombinant strains, is based on the formulation described by Miller. E. coli is grown to late log phase in LB Medium. Some plasmid vectors replicate to a high copy number and do not require selective amplification. Some vectors do not replicate so freely and need to be selectively amplified. Chloramphenicol may be added to inhibit host synthesis and prevent replication of the bacterial chromosome.

LB Agar, Miller contains 10g/L of sodium chloride, different from the levels in Lennox formulations. This allows the researcher to select the optimal salt concentration for a specific strain. The medium may be aseptically supplemented with glucose or antibiotics.

• Analyte: non-selective
• Platform: dehydrated culture media
• Formula: tryptone 10.0g/L, yeast extract 5.0g/L, sodium chloride 10.0g/L, agar 15.0g/L
• Grams per litre: 40.00
• Litres per 500g: 13.00
• Plates per 500g: 680.00