SN/T 5194-2020 in English

Background of Standard Technology Evolution

This standard replaces the 2002 version of SN/T 1162. The main updates include: new fluorescent PCR detection method, optimized virus isolation process, and improved biosafety control requirements. The technical iteration reflects the rapid development of molecular biology detection technology in the past 20 years. The detection sensitivity has increased from 10³ TCID₅₀/mL of traditional cell culture to 10¹ copies/μL of fluorescent PCR.

Comparison of core detection methods

Analysis of key operating points

1. Sample pretreatment

The diseased material should be ground using a high-speed refrigerated centrifuge (≥5,000r/min) in combination with a homogenizer. The PBS buffer must comply with the GB/T 6682 first-level water standard. Notes for double antibody treatment:

• Final concentration of penicillin/streptomycin ≤20,000 IU/mL
• 4℃ induction time ≥12 hours

2. Key parameters for nucleic acid detection

Implementation recommendations

1. Typing detection strategy: Fluorescence PCR is preferred for lip-type cases, and virus isolation and PCR are recommended for hoof-type cases
2. Quality control nodes: Each batch of testing must include:
   • Negative control (PBS blank)
   • Positive control (ATCC VR-634 standard strain)
   • Internal reference gene (such as β-actin)
3. Biosafety: Virus isolation operations should be carried out in a biosafety cabinet, and waste should be sterilized at 121℃ under high pressure for 30 minutes