Used in microbiology laboratories for antibiotic susceptibility testing to determine the effectiveness of bacitracin against various bacterial strains, particularly in identifying Group A Streptococcus (Streptococcus pyogenes) based on its sensitivity. Also employed as a reference standard in quality control processes for pharmaceutical formulations containing bacitracin, ensuring accurate concentration and potency in topical antibiotic products. Widely utilized in research settings for standardizing assays and validating analytical methods such as HPLC and microbiological assays.