Bio-Rad Bio-Plex Pro™ Human Cancer Biomarker Assays - Manual (Page 17)

Lavage, Sputum, and Other Biological Fluid Samples
Keep all samples on ice until ready for use. The appropriate sample
dilution factor should be optimized by the user.
1. If required, dilute the sample in Bio-Plex sample diluent with BSA
added to a final concentration of 0.5%.
2. Centrifugation at 10,000 x g for 10 min at 4°C may be required to
clarify the sample.
Lysates
The Bio-Plex cell lysis kit is required for lysate preparation (available
separately, catalog #171-304011 and #171-304012). Refer to bulletin #5297
for a list of published articles on cytokine analysis in tissue samples.
1. Prepare the cell or tissue lysates according to the instructions
provided with the Bio-Plex cell lysis kit. The protease inhibitors factor I
and factor II are included in the kit. PMSF needs to be added to lysis
buffer at a final concentration of 2 mM. The lysates should be free of
particulate matter.
2. Determine the total protein concentration of the lysate. It may be
necessary to test lyse your samples with different volumes of lysing
solution to obtain the specified protein concentration range.
3. Dilute at least 1:2 in sample diluent + 0.5% BSA, to a final protein
concentration of 50–500 µg/ml.
For optimum antibody binding during sample incubation, it is
important to dilute lysates as much as possible to reduce the
detergent concentration.
4. If the lysate is not tested immediately, store at –20°C. Lysates are
stable for up to five freeze-thaw cycles.
15