Quickly save! Key points for operating ELISA technology
High-quality reagents, proper instrumentation, and standardized procedures are essential for reliable ELISA results
Specimen Collection and Preservation |
1. Specimen Types
ELISA can utilize various biological samples, including body fluids (e.g., serum), secretions (e.g., saliva), and excreta (e.g., urine, feces). Some samples (e.g., serum, urine) can be directly analyzed, while others (e.g., feces) require preprocessing
2. Serum and Plasma Handling
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Serum: The most common specimen for ELISA. Collect blood in sterile tubes, allow clotting at room temperature for 2 hours or overnight at 4°C, then centrifuge at 1,000×g for 20 min. Aliquot and store at -20°C/-80°C to avoid repeated freeze-thaw cycles
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- Avoid hemolysis: Red blood cell lysis releases peroxidase-like substances, causing false positives in HRP-based assays.
- Fresh testing: Use serum promptly to prevent bacterial contamination (bacterial HRP may cause false positives) .
- Plasma: Collect blood with anticoagulants (EDTA, heparin). Centrifuge at 1,000×g for 15 min within 30 min of collection. Follow storage guidelines similar to serum.
3. Storage Guidelines
- Short-term: ≤5 days at 4°C.
- Long-term: Aliquot and store at -20°C (1 month) or -80°C (6 months).
- Thawing: Gently invert to mix; avoid vigorous shaking. Centrifuge turbid samples before use
1. Specimen Types
ELISA can utilize various biological samples, including body fluids (e.g., serum), secretions (e.g., saliva), and excreta (e.g., urine, feces). Some samples (e.g., serum, urine) can be directly analyzed, while others (e.g., feces) require preprocessing.
2. Serum and Plasma Handling
-
Serum: The most common specimen for ELISA. Collect blood in sterile tubes, allow clotting at room temperature for 2 hours or overnight at 4°C, then centrifuge at 1,000×g for 20 min. Aliquot and store at -20°C/-80°C to avoid repeated freeze-thaw cycles
.
- Avoid hemolysis: Red blood cell lysis releases peroxidase-like substances, causing false positives in HRP-based assays.
- Fresh testing: Use serum promptly to prevent bacterial contamination (bacterial HRP may cause false positives).
- Plasma: Collect blood with anticoagulants (EDTA, heparin). Centrifuge at 1,000×g for 15 min within 30 min of collection. Follow storage guidelines similar to serum.
3. Storage Guidelines
- Short-term: ≤5 days at 4°C.
- Long-term: Aliquot and store at -20°C (1 month) or -80°C (6 months).
- Thawing: Gently invert to mix; avoid vigorous shaking. Centrifuge turbid samples before use