BALBcJ

BALB/cJ is an inbred laboratory mouse strain used in biomedical research. It is a substrain of BALB/c and is maintained by The Jackson Laboratory (JAX) in the United States. The J suffix identifies this lineage within the BALB/c family, which includes several substrains developed by different breeders. BALB/cJ is widely used alongside other BALB/c substrains to study immune responses, cancer, and infectious diseases.

BALB/cJ mice are albino, a phenotype due to a mutation at the tyrosinase (Tyr) gene. As an inbred strain, BALB/cJ exhibits high homozygosity across the genome, providing a stable genetic background for experiments and enabling reproducibility across laboratories. They are generally characterized by a Th2-biased immune profile, tending toward strong antibody responses and comparatively weaker cell-mediated immunity. This immunological tendency influences their suitability for certain infection, allergy, and vaccine studies.

Common applications include immunology, oncology, infectious disease, and toxicology research. BALB/cJ mice serve as hosts for syngeneic tumor models (for example, mammary tumor lines studied in BALB/c backgrounds) and are frequently used for monoclonal antibody production and hybridoma work. They are also valuable for genetics and developmental biology studies due to their well-documented, stable genome.

Genetic resources and substrains: The BALB/c lineage comprises several substrains, such as BALB/cJ and BALB/cByJ, which share ancestry but display minor genetic differences. Researchers select substrains based on experimental needs. The BALB/cJ genome has been incorporated into broader mouse reference panels, supporting SNP and haplotype analyses and cross-strain comparisons.