Clinical analyzer wash and method

Abstract

A clinical analyzer has been described that includes a probe to aspirate a fluid. The probe is washed between aspirations to reduce carryover. The wash operation includes both an internal and an external wash, where the internal wash operation is terminated prior to terminating the external wash. In one example, the probe wash can be implemented on an integrated clinical chemistry/immunoassay analyzer.

What is claimed is: 
     
         1 . A method comprising:
 determining a sampling volume of a test sample aspirated by a probe of an analyzer;   flushing an interior region of the probe with wash fluid for X seconds; and   flushing an exterior surface of the probe with the wash fluid for Y seconds, the flushing of the interior region and the exterior surface occurring at least partially simultaneously, wherein the flushing of the exterior surface is to terminate after the flushing of the interior region is to terminate, and wherein Y is based on the sampling volume.   
     
     
         2 . The method of  claim 1 , wherein Y is a first duration of time if the sampling volume is less than a threshold, and Y is a second duration of time if the sampling volume is greater than the threshold, the second duration of time being greater than the first duration of time. 
     
     
         3 . The method of  claim 2 , wherein the second duration of time is about three times longer than the first duration of time. 
     
     
         4 . The method of  claim 1 , wherein the flushing of the exterior surface is to terminate about 0.1 second after the flushing of the interior region is to terminate. 
     
     
         5 . The method of  claim 1 , wherein the flushing of the exterior surface starts prior to the flushing of the interior region. 
     
     
         6 . The method of  claim 1 , wherein determining the sampling volume comprises subtracting a volume of buffer fluid, which is aspirated prior to an aspiration of the sampling volume, from a total aspirated volume.