ELISA Sample Collection & Storage
Ascitic Fluid
- Remove particulates by centrifugation for 15 minutes at 10,000x g at 2–8°C and assay immediately or aliquot and store samples at -20°C.
- Avoid repeated freeze-thaw cycles.
Breast Milk
- Centrifuge for 15 minutes at 10,000x g at 2–8°C.
- Collect the aqueous fraction and centrifuge twice more for a total of 3 cycles.
- Assay immediately or aliquot and store at ≥ -20°C.
- Avoid repeated freeze-thaw cycles.
Bronchoalveolar Lavage Fluid
- Remove particulates by centrifugation for 15 minutes at 10,000x g at 2–8°C and assay immediately or aliquot and store samples at -20°C.
- Avoid repeated freeze-thaw cycles.
Cell Culture Supernates
- Remove particulates by centrifugation for 15 minutes at 1000 x g, 2–8°C and assay immediately or aliquot and store samples at -20°C or -80°C.
- Avoid repeated freeze-thaw cycles.
Cell Lysates
- Remove media and rinse cells once with ice-cold PBS (pH 7.0-7.4).
- Scrape cells off the plate and transfer to an appropriate tube.
- Dilute cell suspension with 1xPBS (pH 7.0-7.4), until cell concentration reached 100 million/ml then store overnight at -20°C.
- After two freeze-thaw cycles to break up the cell membranes, the cell lysates were centrifuged for 5 minutes at 5000 g, 2 - 8°C.
- Collect the supernatant.
- Cell lysates should be assayed immediately or aliquotted and stored at -20°C.
- Centrifuge the sample again after thawing before the assay.
- Avoid repeated freeze-thaw cycles.
Cerebrospinal Fluid (CSF)
- Remove particulates by centrifugation for 15 minutes at 10,000x g at 2–8°C and assay immediately or aliquot and store samples at -20°C.
- Avoid repeated freeze-thaw cycles.
Lysate for RBC
- Centrifuge 100ul blood sample at 2000rpm for 5min at 2–8°C to collect the RBC.
- Remove supernate and add 10ml ice-cold PBS (pH 7.0-7.4) then store overnight at -20°C.
- After three freeze-thaw cycles to break up the cell membranes, the cell lysates were centrifuged for 10 minutes at 10000rpm, 2–8°C.
- Collect the supernatant.
- RBC lysates should be assayed immediately after 5000-fold dilution or aliquotted and stored at -20°C.
- Centrifuge the sample again after thawing before the assay.
- Avoid repeated freeze-thaw cycles.
Plasma
- Collect plasma using EDTA, or heparin as an anticoagulant.
- Centrifuge for 15 minutes at 1000 x g, 2–8°C within 30 minutes of collection.
- Assay immediately or aliquot and store samples at -20°C or -80°C.
- Centrifuge the sample again after thawing before the assay.
- Avoid repeated freeze-thaw cycles.
Pleural Effusion
- Remove particulates by centrifugation for 15 minutes at 10,000x g at 2–8°C and assay immediately or aliquot and store samples at -20°C.
- Avoid repeated freeze-thaw cycles.
Saliva
- Remove particulates by centrifugation for 15 minutes at 10,000x g at 2–8°C and assay immediately or aliquot and store samples at -20°C.
- Avoid repeated freeze-thaw cycles.
Serum
- Use a serum separator tube (SST) and allow samples to clot for 30 minutes before centrifugation for 15 minutes at 1000 x g, 2–8°C.
- Remove serum and assay immediately or aliquot and store samples at -20°C or -80°C.
- Centrifuge the sample again after thawing before the assay.
- Avoid repeated freeze-thaw cycles.
Solid Samples (feces)
- Prepare with Sample Diluent (1:10).This can be achieved by adding 0.1g solid sample to 1ml of Sample Diluent.
- Centrifuge and collect the supernates for assay.
Tissue Homogenates
- 100mg tissue was rinsed with 1X PBS, homogenized in 1 mL of 1X PBS and stored overnight at -20°C.
- After two freeze-thaw cycles were performed to break the cell membranes, the homogenates were centrifuged for 5 minutes at 5000 x g, 2 - 8°C.
- The supernate was assayed and removed immediately
- Alternatively, aliquot and store samples at -20°C or -80°C.
- Centrifuge the sample again after thawing before the assay.
- Avoid repeated freeze-thaw cycles.
Urine
- Collect urine using a metabolic cage.
- Remove any particulates by centrifugation for 15 minutes at 1000x g, 2–8°C and assay immediately or aliquot and store samples at -20°C or -80°C.
- Centrifuge again before assaying to remove any additional precipitates that may appear after storage.
- Avoid repeated freeze-thaw cycles.