The ELx405TM Washer A Family of Washer to Meet the Diverse Needs of Biological Screening

To address the diversity of microplate washing requirements, BioTek has developed the ELx405TM, a family of microplate washers that provides versatility, as well as dedicated capabilities. The ELx405 Select Microplate Washer uses a patented manifold design which provides independent control of aspirate and dispense tube location and height enabling bubble free fluid dispense and overflow protection in 96and 384-well plates. Other models include the ELx405TM HT, which is a dedicated 384-well microplate washer, based on the same manifold design. The ELx405 Select CW was designed to wash loosely adherent cells, while the ELx405 Magna can be used for magnetic bead assays. Maintenance problems have been reduced by the introduction of the patent-pending Ultrasonic AdvantageTM design, which provides ultrasonic cleaning of the manifold on most ELx405 washers. An overview of the ELx405 washer family, data demonstrating the washer’s accuracy and precision, evacuation efficiency, as well as speed and timing will be included. Introduction The ELx405 family of washers has been designed to meet the challenges of various applications, reliability, easy maintenance, yet cost effectiveness (Figure 1). The ELx405 series of washers use BioTek Instruments’ patented manifold design to overcome the difficulties presented by high density microplates and allows virtually the same functionality to be applied to the 16x24 matrix 384-well plates as that is expected with the 8x12 formatted 96-well microplate. As seen in Figure 2, the dispense and aspiration manifolds are placed into two physically different Figure 1. ELx405 Microplate Washer parts that are arranged on top of each other. The lower manifold (dispense) is constructed in such a manner as to allow the tube from the above manifold (aspiration) to pass through and enter the well of the microplate. In order for the dispense pipe to be able to dispense fluid into a small well while the aspirate pipe is removing fluid from the same well, as is the situation when overflow and bottom washing is performed, the dispense pipe is tilted from vertical (Figure 2.) This allows for the dispense pipe to be offset from the center of the well, providing room for the aspiration pipe, yet still allowing the fluid jet to enter BioTek Instruments, Inc., P.O. Box 998, Highland Park, Winooski, Vermont 05404-0998 USA COPYRIGHT © 2006 TEL: 888-451-5171 FAX: 802-655-7941 Outside the USA: 802-655-4740 E-mail: [email protected] www.biotek.com the well from the side. This canted design also has the added benefit of providing a swirling motion of the fluid that results in a more vigorous wash. ELx405 Select Manifold Assembly Figure 2. Schematic side view of the Washer Manifold Assembly. The aspiration and dispense manifolds are physically separated to allow for individual control of each manifold. The angled dispense pipes allow for a swirling fluid movement into the well, while allowing simultaneous access of the aspiration tube to the same well in a 384-well microplate. This unique patent pending design provides independent height control enabling bubble-free fluid dispense and overflow protection in 96and 384-well microplates. In order to meet the needs of a variety of different users, a family of ELx405 washers has been developed. The ELx405 Select is a multifunctional microplate washer that can wash both 96and 384-well microplates without any mechanical changes required. This washer has 96 pairs of tubes (aspiration and dispense) that can wash all 96-wells of a 96-well plate simultaneously or wash 384-well plates in four quadrants without any manifold change. Plate type is simply selected from the software keypad. The ELx405 Magna is a 96-well microplate washer designed to wash magnetic bead based assays. By integrating strong rare-earth magnets into the plate carrier, ferrite beads can be captured as needed to allow fluid aspiration without loss. Removal of the magnet then allows complete washing of the beads. The ELx405 is a standard 96-well microplate washer for those with conventional ELISA plate washing needs. In addition to these washers, BioTek has developed washers that address specific customer needs. The ELx405 HT, which is a dedicated 384-well microplate washer that utilizes 192 pairs of aspiration and dispense pipes has been optimized for speed, to provide rapid and effective aspiration and dispensing of fluid yet have all of the features associated with 96-well plate washers for HTS customers. Where speed is essential, each complete wash cycle is run in less than 19 seconds. The ELx405TM Select CW has been designed for the most difficult cell washing applications. Many loosely attached cell lines can be disrupted by the slowest fluid dispense-rate of typical washers. The ELx405TM Select CW incorporates a dual fluid path and software control designed specifically to lower the dispense rate to the lowest possible flow, without affecting dispense accuracy and precision (Figure 3). When the new low-flow rates are selected from the keypad menu, the flow control valve directs all fluid movement through the “low flow line”, which has the ability to restrict flow to extremely low rates. When standard rates are selected the flow control valve opens, allowing full fluid movement through the system. As in a standard washer configuration.