QC Sample of Escherichia coli O157:H7 in Food - Basic Information

Recommended Medium	Peptone: 10.0g, Beef Extract Powder: 3.0g, Sodium Chloride: 5.0g, Agar: 15.0g, pH: 7.3±0.1 (25℃)
Growth Conditions	37℃, aerobic
Growth Characteristics	The strain is cultured on nutrient agar (Recommended Medium) at 37℃ for 3 days; the cells are rod-shaped, 0.61μm × 1.22–2.13μm, Gram-negative, non-spore-forming.
Storage Conditions	-20℃
Isolation Source	Blood culture
Procedure	① First, culture the strain into a bacterial suspension according to the culture conditions; ② Measure the absorbance of the bacterial suspension and calculate the initial concentration of the suspension using the standard formula; ③ Multiply the initial concentration by the survival rate to obtain the actual concentration after lyophilization; ④ Dilute the bacterial suspension based on the actual post-lyophilization concentration to obtain the target concentration, then aliquot and lyophilize;
Intended Use	Personnel proficiency assessment
Sharing Method	Public welfare sharing