GB 4789.12-2025 National food safety standard -Food microbiological examination - Examination of botulinum neurotoxin-producing Clostridia and botulinum neurotoxin
1 Scope
This standard specifies the examination methods for botulinum neurotoxin-producing Clostridia and botulinum neurotoxin in food.
This standard is applicable to the examination of botulinum neurotoxin-producing Clostridia and botulinum neurotoxin in food.
2 Terms and definitions
botulinum neurotoxin-producing Clostridia
a general term for Gram-positive anaerobic bacilli that can form oval spores, generally larger than the cell and located subterminally, and are capable of producing botulinum neurotoxin under suitable culture conditions, including Clostridium botulinum, Clostridium butyricum, etc.
3 Equipment and materials
In addition to conventional sterilization and incubation equipment used in microbiological laboratories, other equipment and materials required are as follows.
3.1 Refrigerator: 2°C~8°C, -18°C~-20°C, and -80°C.
3.2 Balance: sensitivity of 0.1g and 0.001g.
3.3 pH meter, pH colorimetric tube, or precision pH test paper.
3.4 Sterile scissors, forceps, and reagent spoon.
3.5 Stomacher blender or sterile mortar.
3.6 Centrifuge: 3 000g and 14 000g.
3.7 Anaerobic culture devices: anaerobic incubator, anaerobic jar, anaerobic bag, or devices providing equivalent anaerobic effect.
3.8 Constant temperature incubator: 36°C±1°C and 28°C±1°C.
3.9 Constant temperature device: 36°C±1°C, 60°C±1°C, 80°C±1°C, and 100°C±1°C.
3.10 Microscope: 100×~1 000×.
3.11 Conventional PCR instrument and real-time fluorescence PCR instrument.
3.12 Conventional electrophoresis apparatus or capillary electrophoresis apparatus.
3.13 Gel imaging system or ultraviolet detector.
3.14 Nucleic acid protein analyzer or ultraviolet spectrophotometer.
3.15 Micropipettes and matching sterile tips: 2 μL, 10 μL, 20 μL, 100 μL, 200 μL, 1 000 μL.
3.16 Sterile pipettes: 1 mL (with 0.01 mL graduations), 10 mL (with 0.1 mL graduations), and 25 mL (with 0.1 mL graduations).
3.17 Sterile conical flasks: 100 mL.
3.18 Petri dishes: diameter of 90 mm.
3.19 Centrifuge tubes: 1.5 mL, 5 mL, and 50 mL.
3.20 Sterile filters: membranes with pore sizes of 0.45 μm and 0.22 μm.
3.21 PCR reaction tubes.
3.22 Sterile syringes: 1 mL.
3.23 Mice: body weight of 15g to 20g. Each batch of tests shall use KM (Kunming) or ICR mice of the same strain and single sex, the weight difference between individuals of the same sex shall not exceed ±20% of the average weight, and if female, they shall be unmated and non-pregnant.
Contents
Foreword i
1 Scope
2 Terms and definitions
3 Equipment and materials
4 Culture media and reagents
5 Examination procedures
6 Operation steps
7 Results and report
Annex A Culture media and reagents
