GB/T 40265-2021 in English

Analysis of the core content of the standard

Key technical requirements

1. Laboratory environment control

The standard clearly stipulates that the clean area must meet the ISO6 level suspended particle concentration requirements (refer to GB/T25915.1), and the biosafety level should meet the requirements of GB19489. Special requirements include:

• Protein samples need to be stored at <8℃
• Use hydrophilic surface ELISA plates
• The wash buffer must contain 0.05% Tween-20

2. Key points for antibody titer determination

When using the indirect ELISA method (Appendix D):

1. Antigen coating concentration 10-20μg/mL (carbonate buffer pH 9.6)
2. Initial antibody dilution ratio 1:1000
3. Judgment criteria: Positive when absorbance ≥ 2 times of blank control

Implementation recommendations

Method selection strategy

Cross-reaction control

When the CR value>＞5% (Appendix F calculation formula), the possible risk of false positives must be noted in the test report. It is recommended that:

1. Use the SPR method to verify cross-reaction
2. Optimize the antibody dilution ratio
3. Add structural analog blocking experiments