Storing the plate overnight prior to analysis has not been validated by R&D Systems. It is recommended that users validate deviations from the recommended protocol in their laboratory to ensure accurate and reproducible results.
Controls are available for the Human Luminex High Performance Assays. The control set specific to the panel can be found under the Supplemental Products tab on the product specific web page.Please contact Technical Service for additional information about these controls.
No, analytes from separate Luminex Performance Assay panels cannot be combined. The base kits contain the standard curves for only those analytes recommended for that specific panel. All buffers and reagents have been optimized for the analytes within that panel and may not be compatible with analytes represented in other panels.
The difficulties of running multiplex beads in a flow cytometer is the inability to distinguish the different bead sets since they are stained with dyes that are optimally excited with a YAG laser. If a customer wishes to run a single bead population (IL-8 only for example), one would need the ability to discriminate different beads with different analyte capturing abilities. Also, since the bead assays are developed with PE-conjugated antibodies, the argon laser of most flow cytometers will be able to generate a signal from these beads. Keep in mind that this does not utilize the full potential of the Luminex Assay kits.
The best method for washing magnetic beads is use of a magnet. However, magnetic beads can be washed using a vacuum manifold and a filter-bottom plate. Magnetic beads are actually larger than the polystyrene (6.4 vs 5.6 um) so there is little risk for the beads to be pulled through the filter with a standard filter bottom plate (Millipore, Cat# MSBVN1B50). Prior to reading the assay, add an extra shaking at the final re-suspension step to be extra sure the beads are free from the plate.
Running the whole plate at one time is not necessary. If running a partial plate, R&D Systems recommends covering the unused portion since the wells are not in removable strips. That way the unused portion of the plate will not be contaminated. Reusing of wells in the plate is not recommended.
R&D Systems does not add HBT reagents to diluents, but instead formulates specialized diluents that are designed to alleviate false positives to achieve the most accurate results. Our diluents are designed to minimize interfering factors such as binding partners, soluble receptors, HAMA, and rheumatoid factor. With R&D Systems immunoassays, it is not necessary to add heterophilic blocking reagents to the samples.
The cost of R&D Systems Luminex kits can vary depending on how many analytes are plexed together. Pricing information can be found on our Luminex Ordering Tool located here: https://www.rndsystems.com/luminex/analytesIf assistance with pricing is still needed, please contact Customer Care.
Our Luminex ordering tool is designed to alert you if any analytes are not able to be multiplexed. If analytes cannot be plexed together this can be due to known interference or the same bead region has been selected. If you are having difficulties determining if the analytes can be plexed together, please contact our Technical Support.
Environmental stewardship is important to R&D Systems and its employees. R&D Systems regularly explores "green" options. First and foremost, the energy expended to ship back the styrofoam box is more detrimental to the environment than having the facility re-use or recycle it. Our stance is to encourage our customers to implement a recycling program locally and we can identify a recycling center for styrofoam nearest your facility if necessary. At R&D Systems we have chosen to reduce the use of styrofoam as much as possible by: Doing extensive stability testing in order to determine which products can be shipped with minimal packaging at ambient temperatures, Converting the use of non-recyclable packaging materials to recyclable plastics, cardboard, or biodegradable materials, and Continuing to investigate alternatives to dry ice shipments, the use of re-usable containers, and gel packs that allow for smaller styrofoam containers. Employees were key to initiating a recycling program at our facilities. Internally, we recycle paper, plastic, cardboard, aluminum, glass, and styrofoam.
The lower limit of detection (LOD) is also known as the minimum detectable dose (MDD). This is calculated by adding two standard deviations to the mean optical density value of twenty zero standard replicates and calculating the corresponding concentration. The value obtained from this calculation is considered the absolute minimum value that could be distinguished from the background.The lower limit of quantification (LLOQ) is the lowest point on standard curve. This value will give the lowest quantifiable concentration value in samples. Any sample values that fall below that of the lowest standard should be reported as less than the LLOQ.
In general the sensitivity of the Luminex Assays and Luminex High Performance Assays is simillar. A High Performance Assay consists of select analytes which have been thoroughly tested and validated together as a panel. The diluents provided in the High Performance kits and assay conditions have been optimized for best results with the analytes on the same panel. The High Performance Assay is the most precise, reproducible and accurate Luminex tool offered by R&D Systems. Controls are available for the Human Luminex High Performance Assays.The Luminex Assay option is a flexible tool, providing the uncommon opportunity to customize by mixing and matching analytes across different panels. Although not as extensively tested as the High Performance Assays, analytes on a Luminex Assay are tested together when built and a final quality control test on each Luminex Assay is performed prior to release. Since each Luminex Assay is unique and built to order, additional days are required for order fulfillment and it is not characterized by the same level of optimization and validation testing as with the High Performance assays. Controls are not available for Luminex Assay.For low abundance cytokines, High Sensitivity panels are available for High Performance Assay, which are not available for Luminex Assay.
R&D Systems does not determine the half life of cytokines in natural samples such as serum, plasma, or cell culture supernates. Our general recommendation is to assay the sample immediately or aliquot into single use volumes and store these samples frozen. We recommend avoiding repeat freeze-thaw cycles with these samples to avoid protein degradation.
Due to possible variations in techniques, methodologies, and type of instruments, R&D Systems does not provide ranges for its Luminex High Performance controls and recommends that each laboratory determine its own control range. R&D Systems provides target mean values which end users can use for initial determination of their own acceptability range based on tolerance of variations in each laboratory. It is suggested to use the target mean value +/-30%. Note that R&D Systems does not offer kit controls for Luminex Discovery Assays.
The product datasheet describes the protocol and validation of the assay which does not change from lot-to-lot. The standard value card is specific for the lot of product manufactured and contains lot-specific values. Please contact Technical Service (firstname.lastname@example.org) and provide the kit catalog # and lot # if additional standard value cards are needed.
R&D Systems immunoassay standards are calibrated against an internal "Master Calibrator" to ensure consistency of the standard curve and sample values from lot-to-lot. The challenge when comparing immunoassay results from different vendors is that there is no single Master Calibrator for each analyte that is used by all vendors. Calibration, coupled with other variables (such as antibodies, detection methods, buffers, and cross-reactivity/interference) can lead to differences in sample values from different vendors’ assays.
Controls are assigned an expiration date of 3 months from date of receipt. They are to be used once and discarded. If the lyophilized controls are stored properly, it is possible that they will remain stable for an extended period of time, although we have not conducted extended stability testing. The controls have not been tested for stability after reconstitution.