GB 4789.42-2025 National food safety standard - Food microbiological examination - Norovirus
1 Scope
This standard specifies a real-time fluorescence RT-PCR examination method for Norovirus in food.
This standard is applicable to the detection of norovirus in shellfish, raw vegetables, hard surface foods, soft fruits and packaged drinking water.
2 Equipment and materials
In addition to conventional sterilization and incubation equipment used in microbiological laboratories, other equipment and materials required are as follows:
2.1 Real-time fluorescence PCR.
2.2 Cryogenic centrifuge: with centrifugal force >12,000×g, temperature ≤4℃; the casing volume is suitable for 1.5mL/50mL centrifuge tube.
2.3 Sterile blade or equivalent homogenizer.
2.4 Vortex mixer.
2.5 Electronic balances: with sensitivities of 0.1g and 0.1mg, respectively.
2.6 Full temperature oscillator or equivalent device: with a temperature range of 2℃ to 60℃.
2.7 Constant temperature water bath or constant temperature metal bath: with a temperature range of room temperature ~100℃.
2.8 Centrifuge: with centrifugal force >5,000×g; the casing volume is suitable for 50mL/15mL centrifuge tube.
2.9 Cryogenic freezer: -80℃.
2.10 Micropipette.
2.11 pH meter or precision pH test paper.
2.12 Aseptic homogeneous bag: 400mL (volume), with a filter screen.
2.13 Sterile cotton swabs.
2.14 Sterile shellfish shucker.
2.15 Rubber pad.
2.16 Sterile scissors.
2.17 Sterile tweezers.
2.18 Aseptic culture dish.
2.19 RNase-free glassware, RNase-free centrifuge tube, RNase-free pipette tip, RNase-free spatula, RNase-free PCR thin-walled tube: See E.1 of Annex E.
2.20 Ultrafiltration concentration centrifuge tube (with a cut-off protein molecular weight of 50kD or 100kD).
2.21 Sterile mixed cellulose membrane (with a pore size of 0.45μm, and a diameter of 47mm).
3 Culture media and reagents
Unless otherwise specified, analytically-pure reagents shall be adopted for all experiments; and RNase-free ultrapure water (see E.2.1) shall be adopted for the experiment.
3.1 Primers and probes of GI and GII of norovirus: See Annex A.
3.2 Process control virus primers and probes: See Annex C.
3.3 Process control virus: Mengovirus or escherichia coli phage MS2, See Annex C.
3.4 External amplification control RNA: See Annex D.
3.5 Tris/glycine/beef extract (TGBE) buffer: See E.2.2.
3.6 5×PEG/NaCl solution: See E.2.3.
3.7 Phosphate buffer solution (PBS): See E.2.4.
3.8 Chloroform/n-butanol mixture: See E.2.5.
3.9 Proteinase K solution: See E.2.6.
3.10 75% ethanol: See E.2.7.
3.11 Trizol reagent: See E.2.8.
3.12 Hydrochloric acid (HCl) solution (6mol/L): See E.2.9.
3.13 Sodium hydroxide (NaOH) solution (1mol/L): See E.2.10.
Foreword i
1 Scope
2 Equipment and materials
3 Culture media and reagents
4 Examination procedures
5 Operation steps
6 Results and report
7 Others
Annex A Primers and probes for real-time fluorescence RT-PCR
Annex B Reaction system and parameters of real-time fluorescence RT-PCR
Annex C Process control virus culture as well as primers and probes used
Annex D Preparation of external amplification control RNA
Annex E Removal of RNase and preparation of RNase-free solutions
Standard
GB 4789.42-2025 National food safety standard - Food microbiological examination - Examination of Norwalk Viruses (English Version)
Standard No.
GB 4789.42-2025
Status
valid
Language
English
File Format
PDF
Word Count
8000 words
Price(USD)
240.0
Implemented on
2025-9-16
Delivery
via email in 1 business day
Detail of GB 4789.42-2025
Standard No.
GB 4789.42-2025
English Name
National food safety standard - Food microbiological examination - Examination of Norwalk Viruses
Chinese Name
食品安全国家标准 食品微生物学检验?诺如病毒检验
Chinese Classification
Professional Classification
GB
ICS Classification
Issued by
National Health Commission of the People's Republic of China, State Administration for Market Regulation
GB 4789.42-2025 National food safety standard - Food microbiological examination - Norovirus
1 Scope
This standard specifies a real-time fluorescence RT-PCR examination method for Norovirus in food.
This standard is applicable to the detection of norovirus in shellfish, raw vegetables, hard surface foods, soft fruits and packaged drinking water.
2 Equipment and materials
In addition to conventional sterilization and incubation equipment used in microbiological laboratories, other equipment and materials required are as follows:
2.1 Real-time fluorescence PCR.
2.2 Cryogenic centrifuge: with centrifugal force >12,000×g, temperature ≤4℃; the casing volume is suitable for 1.5mL/50mL centrifuge tube.
2.3 Sterile blade or equivalent homogenizer.
2.4 Vortex mixer.
2.5 Electronic balances: with sensitivities of 0.1g and 0.1mg, respectively.
2.6 Full temperature oscillator or equivalent device: with a temperature range of 2℃ to 60℃.
2.7 Constant temperature water bath or constant temperature metal bath: with a temperature range of room temperature ~100℃.
2.8 Centrifuge: with centrifugal force >5,000×g; the casing volume is suitable for 50mL/15mL centrifuge tube.
2.9 Cryogenic freezer: -80℃.
2.10 Micropipette.
2.11 pH meter or precision pH test paper.
2.12 Aseptic homogeneous bag: 400mL (volume), with a filter screen.
2.13 Sterile cotton swabs.
2.14 Sterile shellfish shucker.
2.15 Rubber pad.
2.16 Sterile scissors.
2.17 Sterile tweezers.
2.18 Aseptic culture dish.
2.19 RNase-free glassware, RNase-free centrifuge tube, RNase-free pipette tip, RNase-free spatula, RNase-free PCR thin-walled tube: See E.1 of Annex E.
2.20 Ultrafiltration concentration centrifuge tube (with a cut-off protein molecular weight of 50kD or 100kD).
2.21 Sterile mixed cellulose membrane (with a pore size of 0.45μm, and a diameter of 47mm).
3 Culture media and reagents
Unless otherwise specified, analytically-pure reagents shall be adopted for all experiments; and RNase-free ultrapure water (see E.2.1) shall be adopted for the experiment.
3.1 Primers and probes of GI and GII of norovirus: See Annex A.
3.2 Process control virus primers and probes: See Annex C.
3.3 Process control virus: Mengovirus or escherichia coli phage MS2, See Annex C.
3.4 External amplification control RNA: See Annex D.
3.5 Tris/glycine/beef extract (TGBE) buffer: See E.2.2.
3.6 5×PEG/NaCl solution: See E.2.3.
3.7 Phosphate buffer solution (PBS): See E.2.4.
3.8 Chloroform/n-butanol mixture: See E.2.5.
3.9 Proteinase K solution: See E.2.6.
3.10 75% ethanol: See E.2.7.
3.11 Trizol reagent: See E.2.8.
3.12 Hydrochloric acid (HCl) solution (6mol/L): See E.2.9.
3.13 Sodium hydroxide (NaOH) solution (1mol/L): See E.2.10.
Contents of GB 4789.42-2025
Foreword i
1 Scope
2 Equipment and materials
3 Culture media and reagents
4 Examination procedures
5 Operation steps
6 Results and report
7 Others
Annex A Primers and probes for real-time fluorescence RT-PCR
Annex B Reaction system and parameters of real-time fluorescence RT-PCR
Annex C Process control virus culture as well as primers and probes used
Annex D Preparation of external amplification control RNA
Annex E Removal of RNase and preparation of RNase-free solutions
