Sample Dilution Guide

For our cytokine array Discovery Assays, dilute your samples using standard PBS pH~7.5 prior to shipping for the following cases (refer to Table 1 for details):

  1. You are running serum / plasma on mouse or rat cytokines (unless you want results from undiluted samples).
  1. You are running a pilot study at various dilutions.
  1. You previously know your samples require a dilution. For example your pilot study showed a dilution is required.

Our standard procedure for cytokine array Discovery Assays is to run all samples in the dilution format in which we received them.  What this means is you are in direct control of what dilution factor your samples will be run at by sending your samples with the dilution of your choice (PBS pH~7.5 as the dilution buffer).  Prediluting samples generally applies to clients who run serum or plasma on mouse or rat cytokine arrays.  As shown in the table below, most assays recommend samples be run undiluted.  If, however, you are ordering an assay that recommends a dilution (ie. serum/plasma on mouse/rat cytokine arrays), please dilute your samples before sending them to Eve Tech unless you want them run undiluted.  Running a pilot study is recommended to determine the optimal dilution – particularly for variable sample types such as cell cultures, and homogenates.  The benefits of diluting your own samples prior to shipping to Eve Tech are:

  1. The required volume of your precious sample can be reduced by half or more by pre-diluting your samples. For example, without prediluting our mouse and rat cytokine arrays required 50ul of undiluted sample.  If you wish to follow the standard protocol guide of a 2-fold dilution for the mouse and rat cytokine array you would provide aliquots of 25ul of sample diluted in 25ul of PBS pH~7.5.
  1. You are in direct control of what dilution factor your samples will be assayed in. Though the standard protocol for mouse and rat cytokine arrays calls for a 2-fold dilution, some clients prefer to have their samples run either undiluted or at a higher dilution.
  1. Our turn-around time will be improved as this allows us to better batch various sample types.

Refer to Table 1 below or the assay listings on our website for recommended aliquot dilutions.  Our order forms now prompt you to indicate whether you have diluted your samples and at what dilution factor.  Your sample’s dilution factor will be applied to your data set by having the results multiplied by the dilution factor.

Table 1: Required Volumes and Recommended Sample Dilutions
Discovery Assay Volume Required for testing samples in SINGLE Volume Required for testing samples in DUPLICATE Recommended Dilution Factor
Serum, Plasma, Urine, CSF & BALF Cell Culture Supernatant, Tissue Homogenate & Cell Lysate
Human 64-plex Assay 100µl 150µl Undiluted (Note, PDGF-AA, PDGF-BB, RANTES are high in blood samples and may require a dilution. EGF in urine must be run separate at a dilution) Undiluted (Pilot run recommended)
Human 41-plex or 23-plex Assay 50µl 75µl Undiluted (Note, PDGF-AA, PDGF-BB, RANTES are high in blood samples and may require a dilution. EGF in urine must be run separate at a dilution) Undiluted (Pilot run recommended)
Human MMP & TIMP panel 50µl 75µl Undiluted (Eve Tech makes dilution) Undiluted (Eve Tech makes dilution)
Mouse 32-plex Assay 50µl 75µl 2 fold (25ul sample in 25ul PBS pH~7.5) Undiluted (Pilot run recommended)
Rat 27-plex Assay 50µl 75µl 2 fold (25ul sample in 25ul PBS pH~7.5) Undiluted (Pilot run recommended)
Featured Assays Check website for required volume Check website for required volume Check website for required volume Check website for required volume
Custom-Plex Assays (Pilot study recommended if protocol is not specific with sample type) Inquire Inquire Inquire Inquire

How to Dilute your Samples

Dilute your samples in standard PBS pH ~7.5.

2-Fold Dilution:  1 part sample to 1 part buffer (25ul sample to 25ul buffer)

3-Fold Dilution:  1 part sample to 2 parts buffer (17ul sample to 34ul buffer)

Please Note:

Comparing results from diluted samples to undiluted samples can be inaccurate due to the matrix effect and the inaccurate multiplication of baseline signals.  For more information on the matrix effect, sample homogeneity and other factors that cause inaccuracies when comparing results of different dilution factors, please contact us.