Hello! To all those interested in the Luminex technology, Our laboratory has been using the Luminex system for at least 1 and 1/2 years. We presently read the samples on our FACScan. In our laboratory, we have concentrated on screening for soluble human cytokines although we have screened for a few mouse cytokines. The largest combination of human cytokines in one sample has been 28. The beads are from the original lots sold by Luminex for their assay system which was designed for the FACScan. These beads have dyes the emit in the orange and red regions to produce distinct populations in the FL2 vs FL3 bivariate. The system has worked well for us. It is very easy to couple any protein to the carboxylated beads as we have done not only for the anti-cytokine antibodies but for other proteins such a anti-isotype antibodies used for isotype determination. The coupling protocol takes one 8 hour day. The sensistivity of the assay on individual beads (singleplex) approaches and sometimes matches or surpasses that from ELISA data specified from the manufacturer of the ELISA kits. As there is no data for multiplex ELISA assays it is hard to make a comparison with bead multiplex sensitivity. Costwise, the multiplex bead assay is better. Multiple screening assays such as for cytokines can be done in a single tube using as little as 1000 microbeads per cytokine per 100 ul sample. Many times the sample volume is limited and therefore the amount of screens using an ELISA is limited. It is our understanding that the old bead lots will not work with the new Luminex instrumentation and the readout for the newer beads come from emissions which are different from the old lot beads. As I understand, the newer beads cannot be used with a FACScan thereby necessitating the purchase of the new instrument. I believe it would be a worthwhile purchase. The New Luminex system uses a 96 well filter plate technology with appears to greatly enhances throughput by semi-automating the assay procedure. The one caveat is that there is no companion data analysis software with the present system we use and it appears there is none with the new system. Presently we use Microsoft Excel to produce the titer curves and plot analysis of the raw data in mean channel fluorescence (MCF). The best aspect of this system is that it is very flexible in terms of assay development. Any capture antibody or other protein can be coupled to the beads. There is no restriction as with kits in purchasing required reagents or getting unwanted tests along with the specific tests needed. Our cytokine beads have been very stable our the long term (1+ years) interms of titer and sensitivity in various media such as PBS, culture and plasma. Information about the Luminex bead system and results from laboratories that have used the Luminex technologies can be seen at the GLIIFCA meeting in Detroit, Michigan on October 13-15, 2000. Earl Earl A. Timm, Jr. Laboratory of Flow Cytometry Roswell Park Cancer Institute Buffalo, New York 14263
This archive was generated by hypermail 2b29 : Sat Mar 10 2001 - 19:31:33 EST