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Preservation of Streptococcus pneumoniae quality control strains using chocolate agar blocks in glycerol at minus 70
Sindhulina Chandrasingh1, Mahalaxmi Subramaniam1, Sreeja Nair1
1Department of Microbiology, Bangalore Baptist Hospital, Bellary Road, Hebbal, Bengaluru, 560024, Karnataka, India.
Abstract:
We present a method for storage of the quality control strain of S. pneumoniae that could be used in low resource settings. Small blocks of chocolate agar with growth were placed in glycerol (60%V/V) and stored at minus 70 °C. Viability and cultural characteristics were maintained for the testing period of 10 months. The wide availability of both chocolate agar and glycerol make this a suitable alternative to other specialized formulations usually used to maintain stocks of S. pneumoniae ATCC 49619 strain required for quality control of susceptibility testing.

