The PerkinElmer Model C991200 TopCount NXT Microplate Scintillation and Luminescence Counter is capable of counting a variety of beta and gamma emitter labeled samples using liquid or solid scintillators. The time-resolved scintillation counting technique, using individual PMTs, can also be optimized to provide either maximum counting efficiency or maximum sensitivity (maximum efficiency/background ratio). The external plate stacker allows loading of more than 15,000 samples for high unattended counting capacity or integrating the TopCount NXT into a robotic system for unlimited throughput capacity. Because it is based on Windows 2000, the TopCount NXT is easy to network and enables error-free, automatic data transfers. Best of all, you never lose data due to printer or network failures as the integrated hologram database automatically saves data for each sample counted. Uncompromised performance with cross-talk-free microplate counting. Characteristics:. The automatic microplate stacker holds cassettes for twenty or forty plates. Twenty-plate cassettes can hold twenty 384-well microplates, twenty 96-well microplates, or fifteen 24-well microplates. The forty plate cassettes accommodate forty 384-well microplates, forty 96-well microplates, or thirty 24-well microplates. The stacker offers a fully automatic loading, counting, unloading and repeat cycle for sample plate batches. Microplates can be mixed in the twenty or forty plate VariPlate format cassettes of the TopCount NXT system. 24-well microplates cannot be counted in the TopCount NXT HTS system. The external stacking cassettes allow plates to be loaded and unloaded without interrupting sample evaluation. To operate a TopCount NXT system, two stacking cassettes for twenty or forty plates are required. Patented TR-LSC® three-mode counting technology ensures optimal sensitivity for luminescence, liquid or solid scintillation counting. TopCount NXT is the only microplate counter on the market that can analyze luminescence samples with single photon counting and liquid and solid scintillation samples with single PMT, time-resolved coincidence counting. Optical crosstalk is prevented in 24-well and 96-well opaque microplates through the use of reflective optics and patented single photomultiplier tube technology. This technology allows the use of opaque plates that prevent light transmission between wells. Minor crosstalk in 384-well microplates caused by extremely thin well walls is corrected by proprietary crosstalk correction software. An isothermal counting chamber maintains a constant counting temperature for all tests. This eliminates electronic drifts and ensures reproducible counting conditions even for very temperature-sensitive luminescence reactions. Users can choose the temperature from 19 to 35 °C. The temperature is constantly monitored and can be viewed via an easy-to-read digital temperature display. Unison™ per assay detector normalization sets optimal detector normalization (uniformity) for each assay, regardless of signal type (solid or liquid scintillation or luminescence), plate type, or test medium. DPM calculations via tSIS or optionally tSIE (external standard) provide single and double label DPM, storage of deletion curves, editing of deletion curves on screen and printing of deletion curves. A built-in, IBM-compatible, 350 MHz Pentium II computer with at least 64 MB of RAM (128 MB in 384V and 9912 models), a 3.5-inch 1.44 MB floppy drive, a 4.3 GB -Hard drive, CD-ROM drive, RS-232 input/output, parallel printer port, Windows NT operating system, extended function keys in a pull-out drawer, SVGA color display and mouse. Windows NT with true 32-bit multitasking capability enables simultaneous microplate counting with other Windows or DOS-based applications. The built-in Hologram ODBC database automatically stores all sample counts. This protects the data from printer and network failures and allows users to retrieve the data by plate ID, assay number or date for printing and ASCII file transfer. Two simultaneous counting regions with factory preset and operator customizable counting ranges. Allows single and double label counts, CPM results and single label DPM using the tSIS delete parameter. Counts 3H, 125I, 14C, 35S, 45Ca, 51Cr, 33P and 32P as well as other commonly used beta and gamma nuclides. Supplied with a model 7401279 refrigerated cart, manuals, software, stackers, keyboard and mouse. Labprocure is responsible for this equipment.