Bio-Rad Bio-Plex® Precision Pro™ Human Cytokine Assays - Manual (Page 8)

Section 5
Sample Preparation
This section provides instructions for preparing samples derived from
serum, plasma, and culture supernatant. For sample preparations not
mentioned here, consult the publications listed in Bio-Rad bulletin 5297,
available for download at discover.bio-rad.com
Serum and Plasma Samples
Note that for plasma samples, EDTA tubes are recommended; however,
sodium citrate tubes are acceptable. Extremely lipemic samples may be
filtered with a 0.22 µm filter to prevent clogging. Hemolyzed samples are
not suitable for Bio-Plex
® Precision Pro™ cytokine assays.
1. Collect and process the serum or plasma samples and assay
immediately or freeze at –20ºC. Avoid repeat freezing and thawing.
2. Centrifuge the samples at 13,200 rpm for 10 min at 4ºC
to clear the samples of precipitate. Alternatively, carefully filter the
samples with a 0.22 µm filter to prevent instrument clogging.
3. Immediately dilute 1 volume of sample with 3 volumes of sample
diluent. Keep the samples on ice until ready for use.
Culture Supernatant Samples
1. Collect and process the culture supernatant samples and assay
immediately or freeze at –20ºC. Avoid repeat freezing and thawing.
2. If required, dilute the culture supernatant with culture medium.
Serum-free culture medium should contain carrier protein (such as
BSA) at a concentration of at least 0.5%. Keep the samples on ice
until ready for use.
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