Black 6 (B6NTac)


C57BL/6 Mice - B6 Inbred Mouse Strain - Taconic Biosciences

C57BL/6 Background

  • Model #
  • Genotype
  • Nomenclature
  • B6-F
  • B6-M

Taconic's B6 Provides Superior Versatility and Performance

One of the most versatile inbred mouse strains, the C57BL/6 is commonly used as the genetic background for transgenic mouse models. It is also the preferred model for studying diet-induced obesity and the chronic experimental autoimmune encephalomyelitis model of multiple sclerosis.

  • Superovulated females yield a high number of embryos
  • Males are known to have higher sperm fertilization rates
  • Available at Excluded Flora, Opportunist Free™, Germ Free, and Murine Pathogen Free™ health profiles (Order model #B6 for Murine Pathogen Free™, Opportunist Free™, and Excluded Flora. Order model #GF-B6 for Germ Free.)
  • Popular research applications include addiction, oncology, immunology, metabolic disease, and toxicology
  • Historical data shows that hydrocephaly occurs in the C57BL/6 mouse in 0.05% of the population and may not be evident until the animal is more than two months of age.
  • Preferred Strain for Genetically Engineered Models Generation, including for the Knockout Mouse Project (KOMP) and International Mouse Phenotyping Consortium
  • Proven more amenable to development of quality embryonic stem cells


C57BL/6 litters were received in 1991 at F151 from the NIH Animal Genetic Resource. Cesarean derived in 1991 at Taconic, a foundation colony is maintained in gnotobiotic isolators. Origin is as follows: to NIH in 1951 from Jax at F32; to Jax in 1948 from Hall.


Taconic has established production of model B6 at the Excluded Flora (EF) health standard, which excludes Beta hemolytic Streptococcus (non-Group D), Klebsiella pneumoniae, Klebsiella oxytoca, Proteus spp., Pseudomonas aeruginosa, Staphylococcus aureus and Segmented Filamentous Bacteria. This replaces production of B6 in the US at the Restricted Flora™ (RF) health standard.

Available at a Range of Health Standards
  • Germ-Free
  • Positive or Negative for SFB
  • Ideal for Study Controls
Please contact Taconic with any concerns or questions.


  • Strain Profile: Acy1f, Aladb, Car2a, Cas1g, Cd5b, Cd72b, Cd8ab, Cd8b1b, Ce2a, Es1a, Es3a, Esda, Ggc1b, Gpi1b, Gus-sb, H6pd1b, Hbaa, Hbbs, Hc1, Idh1a, Mod1b, Mup1b, Pep3a, Pgm1a, Trfb
  • Immunology: H2b, Ptprcb, Thy1b, H2-T18b
  • Retinal Degeneration: Crb1Rd8

Coat Color Loci:

a/a, B/B, C/C





Terms of Sale and Use for Black 6 (B6NTac)

Germ Free Black 6 are sold subject to Taconic's Terms and Conditions for the Sale for Products and the following terms of use:

  • For-profit purchasers may not breed Germ Free Black 6 except to obtain embryos or fetuses for research use.
  • Non-profit purchasers may breed Germ Free Black 6 for use in projects at purchaser's institution and on behalf of non-profit researchers only.
  • Germ Free Black 6, progeny and materials derived from them will not be distributed to third parties.
Murine Pathogen Free™, Restricted Flora™ and Excluded Flora Black 6 mice are sold subject to Taconic's Terms and Conditions for the Sale for Products.
Historical data shows that hydrocephaly occurs in the C57BL/6 mouse in 0.05% of the population and may not be evident until the animal is more than two months of age.

C57BL/6NTac substrains carry the Crb1Rd8 mutation.Retinal degeneration 8, is a mild form of retinal degeneration that affects vision. This recessive mutation is a single base pair mutation in the Crb1 gene, Crb1Rd8 (Mehalow et al. 2003) The onset of the phenotype appears to be between 2 and 6 weeks of age (Pritchett-Corning, 2012).

C57BL/6J mice present a deletion (~17 Kbp) in the Nicotinamide Nucleotide Transhydrogenase (Nnt) gene. Nnt is a transmembrane protein that catalyzes the inter conversion of NADH and NADPH in the mitochondria. Studies suggest that the presence of Nnt is essential for mitochondrial defense against oxidative stress and for normal cellular metabolism (Huang et al. 2006). Taconic’s C57BL mice, including C57BL/6JBomTac, C57BL/6NTac and C57BL/10SgSnAiTac, or our B6D2F1 and B6129F1, do not carry the Nnt mutation which is present in C57BL/6J sub-strain.

Reproductive Data

  • Average litter size: 6-8
  • Mean # litters/female: 7
  • Mean age breeder retired: 10 months
  • Mean # days to litter: 22
For some applications, weight may be critical. For orders where weight is critical, please place orders by weight, not by age. Taconic can accept orders by weight for this model, except at the GF health status. A minimum 3 gram span is required. All weights are weights at time of packing. Mice and rats can lose weight in transit. Orders for specific weight spans will be assessed a nominal fee. More detail on weight order policies is available.

n = 500 per sex at MPF, RF and EF health standards from all global colonies. GF mice will typically weigh slightly less than the weights above.
High and low represents mean +/- 2 standard deviations
Based on sample size, the charts above represent ~90% of the population.
All growth curves represent animals housed in our barriers, at our standard density and fed NIH31-M diet. Variations at customer facilities will alter expected growth curves.
Growth charts are provided only as a guide, if a specific weight criteria is needed please order animals by weight.

Customize this chart by clicking the legend elements, then explore download options by hovering your cursor over the down arrow to the right of the chart title.