Abstract:
A dryer for flexible transparent microplate strips used in genetic profiling and methods for drying flexible transparent microplate strips used in genetic profiling. The dryer includes vents for blowing compressed air on the strips and a reel-to-reel design for quickly moving the strips across the vents.

Description:
FIELD OF THE INVENTION 
       [0001]    The invention relates to a step in a genetic profiling technique employing flexible transparent microplate strips with arrays of wells, each containing genetic material to be profiled. More specifically, the invention relates to systems and methods for drying flexible transparent microplate strips after they have been submerged in liquid heating and cooling baths in one or more rounds of the polymerase chain reaction (PCR) and before genetic profiling. 
       BACKGROUND 
       [0002]    Flexible transparent microplate strips (“Strips”), such as the Array Tape™ sold by Douglas Scientific®, provide substrates for highly automated, low volume, fast, and efficient methods for genetically profiling a large number of genetic samples. Genetic profiling methods that use Strips involve sequential automated steps. First, each individual well in a Strip is loaded with genetic materials of interest and a solution of reagents, for example DNA polymerase, DNA bases, and fluorescently labeled SNP probes. The Strip is then covered with a pressure-activated adhesive that seals the materials in the individual wells and prevents leakage between wells or to the external environment. The flexibility of the Strips allows them to be wound around spools that can be more easily handled than unraveled Strips, which can be many feet long. After loading and sealing, spooled Strips are submerged in successive hot and cold baths in one or more rounds of the polymerase chain reaction (PCR) to amplify the genetic material. The resulting Strips must then be dried before they are loaded into an apparatus that probes the material in each well for genetic profiling. In prior art systems, the drying step created a bottleneck in this otherwise fast and efficient genetic profiling method. There thus exists a need in the art for a faster system and method for drying Strips. 
       SUMMARY 
       [0003]    The invention includes a drying apparatus for a flexible transparent microplate strip comprising a pair of opposing air vents formed by elongated or angled holes directed toward the strip and attached to a source of pressurized air, wherein the height of the vents is greater than or approximately equal to the height of the strip. The holes of the drying apparatus may be oriented substantially perpendicular to the length of the microplate strip. The flexible transparent microplate strip may be loaded onto the drying apparatus on a first spool. The flexible transparent microplate strip may be unwound from the first spool, fed between the vents, then wound onto a second spool. 
         [0004]    The drying apparatus may include a source of compressed air and a pressure regulator. The drying apparatus may include a sensor to determine whether a cover is open and electronics that stop a drying operation and turn off air flow when the cover is open. The drying apparatus may include electronics that turn off air flow and stop spool winding when a drying operation is complete. 
         [0005]    The invention includes a method of drying a flexible transparent microplate strip using the drying apparatus described above by pulling the strip between a pair of opposing elongated or angled holes directed toward the strip and attached to a source of pressurized air, wherein the height of the vents is greater than or approximately equal to the height of the strips. 
     
    
     
       DESCRIPTIONS OF THE FIGURES 
         [0006]      FIG. 1  shows an embodiment of an apparatus of the invention. 
           [0007]      FIG. 2  shows a magnification of the region A of  FIG. 1  providing a detailed view of the air blade portion of the  FIG. 1  embodiment. 
           [0008]      FIG. 3  shows a side view of the  FIG. 1  embodiment. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0009]    The invention provides a system and method for drying Strips used in genetic profiling. In the preferred embodiment, the invention includes a spool-to-spool rapid unwinding/winding apparatus, air vents, and an air pressure regulator. The invention provides the benefit of rapidly drying Strips, thus eliminating a bottleneck in common genetic profiling systems. 
         [0010]    In the embodiment of the invention shown in  FIG. 1 , a spool  101  of a Strip is loaded onto a spindle. The free end of the Strip passes through a pair of air vents  102  and is fastened to a second spool  103  on a second spindle. The apparatus includes a user control panel  104  for controlling its operation. A regulator  105  allows control of the air pressure input to the dryer and additional electronic controls allow the operator additional pressure control to allow adjustment of the air speed of the air vents  102 . The apparatus includes a top cover  106  that may be opened to allow loading the Strip and closed during operation to minimize noise and prevent external interference during the drying process. The walls and cover of the drying apparatus may be insulated to further reduce noise levels. Pneumatic strut lift supports  108  assist in opening the cover  106  and holding it open. An integrated sensor provides a shut-off signal to stop the drying operation when the cover is opened. An emergency cut-off switch  109  likewise allows a user to stop the drying operation. A light tower  107  provides users indications as to the status of the apparatus with various colors indicating the machine is idle with no errors, the machine is in operation with no errors, or that an error has occurred. 
         [0011]      FIG. 2  shows a detail of the air vent apparatus of the embodiment shown in  FIG. 1 . Air vent support structure  201  is connected to air vent inlets  202  and  203  on either side of the support structure  201 . Strips are run through the inside portion of the support structure  201 . Lines  204  and  205  direct pressurized air to elongated air vents directed to the inside portion of the support structure  201  to form the high air speed air jets that effect the drying. The elongated air vents are designed to be at least about equal in height to the height of the Strips. Alternatively, the air vents may have a number of angled holes instead of a single elongated air vent to direct high speed air on the Strip. Sensor  206  emits light, which is reflected by reflector  207  to detect the presence of a Strip. Once the sensor  206  detects no strip due to completion of a drying operation, the dryer automatically shuts off and the light tower  107  alerts the operator that the drying cycle is complete. 
         [0012]      FIG. 3  shows a left side detail of the Strip dryer embodiment shown in  FIG. 1 . Pressure regulator  105  includes a pressure adjustment knob  301  and a pressure indicator dial  302 . Air inlet  306  is connectable to a source of pressurized air. Air pressure set by pressure adjustment knob  301  and indicated by the pressure indicator dial  302  is directed to the two air blade inlets  202  and  203  by outlet line  303 . The regulator also includes a filter and a drain  304 . Drain connection  307  can be connected to a drain hose to remove the water that accumulates in the drying apparatus during the drying operation. The air regulator  105  ensures a uniform air pressure inlet to the dryer. Additional electronic controls and an internal air regulator (not shown) allow the operator to select a different air pressure than input at regulator  105  in order to control the air speed from the vents. The dryer includes a main power switch  305 . 
         [0013]    While the  FIG. 1  embodiment has been described in detail to illustrate the invention by one example, it will be readily apparent by those of ordinary skill in the art that modifications may be practiced within the scope of the invention as limited only by the scope of the claims.