Sample Processing for Assays
The Facility for Geroscience Analysis has standard preparation steps for its samples. Below are the preparation steps and information for urine, serum, and platelet-poor plasma. Also, each preparation type has a downloadable pdf version of the figure and steps. If you have any questions, please contact us.
Step 1: After collection, keep urine refrigerated/on ice until processed.
Step 2: Transfer urine to a clean tube.
Step 3: Centrifuge the urine tube at 1400 x g for 10 minutes at 4°C
Step 4a: Transfer urine supernatant to a new clean tube
Step 4b: Cell pellet can be saved for future use. It contains cells and other elements.
Step 5: Aliquot urine supernatant into 1.5ml aliquots until the sample is exhausted.
Step 6: Store Aliquots at -80 °C until used.
Serum can be prepared from whole blood when collected on a tube without anticoagulant, containing or not clot activator. The blood clot can also be collected and frozen for future assays as it is a good source of DNA without preservatives.
Step 1: After the blood draw, keep the blood tube at room temperature for 30 minutes to allow clot formation.
Step 2: Centrifuge the blood tube at 2000 x g for 10 minutes at 4°C
Step 3a: Transfer the serum supernatant to a new clean tube and mix by inverting five times
Step 3b: Optionally the blood clot can be transferred to a new tube and frozen for future use.
Step 4: Aliquot serum into 0.5ml aliquots until the sample is exhausted.
Step 5: Store Aliquots at -80 °C until used
Platelet Poor Plasma Preparation and Buffy Coat Preparation
Platelet-poor plasma and buffy coat can be prepared from whole blood with EDTA, Heparin, or Citrate/ACD as an additive. Buffy coat can be prepared for future use of live cells or not, depending on the assay to be run with those samples.
Platelet-Poor Plasma Preparation
Step 1: After the blood draw, keep/transport blood tube refrigerated/on ice until processed.
Step 2: Centrifuge at 2000 x g for 10 minutes at 4°C
Step 3a: Transfer plasma to a new tube
Step 3b: Collect buffy coat
Step 4: Centrifuge plasma tube at 2000 x g for 10 minutes at 4°C
Step 5: Transfer Plasma Supernatant to new tube Mix by inverting 5 times.
Step 6: Aliquot EDTA/Hep platelet-poor plasma into 0.5ml aliquots until the sample is exhausted.
Buffy Coat Preparation
Step 3b: Transfer Buffy Coat into a 1.5 ml cryovial (Note: If no live cells are needed, freeze the tube at this time)
Step 3c: Add an equal volume of Freezing media and aliquot into two cryovials.
Step 3d: Slow-freeze overnight at -80 oC
Step 3e: Store in liquid Nitrogen