Pipet for liquid exchange

Abstract

The invention features pipets for fast and efficient liquid exchange, pipet controllers for use with such pipets and pipetting systems utilizing pipets and/or pipet controllers of the invention.

What is claimed is:  
     
         1 .- 12 . (cancelled)  
     
     
         13 . A pipet controller comprising 
 a housing having an inlet port and an outlet port, the inlet port adapted to engage a pipet and the outlet port adapted for attachment to a vacuum source;    a conduit within the housing and connected to the inlet port and the outlet port; and    an adjustable valve system for controlling liquid flow through the conduit, the valve system having at least 
 a first setting in which the vacuum source applies a vacuum to the pipet through the conduit, thereby allowing suctioning of liquid from the pipet through the conduit, and  
 a second setting in which the vacuum source is disconnected from the conduit, thereby releasing liquid in the pipet.  
   
     
     
         14 . The controller of  claim 13 , wherein the valve system further has a third setting in which the vacuum source is disconnected but a homeostatic suction is maintained on the pipet.  
     
     
         15 . The controller of any one of claims  13  and  14 , wherein the valve system includes at least one spring-loaded piston.  
     
     
         16 . The controller of  claim 13  or  14 , wherein the controller is formed of only autoclavable materials  
     
     
         17 .- 24 . (cancelled).  
     
     
         25 . The controller of  claim 13  in which the adjustable value system comprises a passage in the housing to the ambient atmosphere, and the second setting exposes the conduit to ambient atmospheric pressure.  
     
     
         26 . The controller of  claim 14  in which the adjustable valve system comprises two pistons.  
     
     
         27 . The controller of  claim 26  in which each of the pistons is biased by a spring.  
     
     
         28 . The controller of  claim 13  that is a handheld controller.  
     
     
         29 . The controller of  claim 13  further comprising a bulb integrated in the conduit.  
     
     
         30 . The controller of  claim 29  wherein the bulb is depressible by a lever.  
     
     
         31 . The controller of  claim 26  wherein one of the pistons comprises a lever that is adapted to pressure a bulb integrated in the conduit.  
     
     
         32 . A method of pipetting liquid, the method comprising: 
 providing a pipet that comprises the controller of  claim 13;     positioning the adjustable valve system at the first setting, thereby applying a vacuum that suctions liquid;    positioning the adjustable value system at the second setting, thereby releasing the vacuum.    
     
     
         33 . The method of  claim 32  wherein the vacuum removes liquid from a vessel to a discard location.  
     
     
         34 . The method of  claim 33  wherein the vacuum both removes liquid from a vessel to a discard location and fills a reservoir in the pipet with liquid, and the vacuum release enables liquid in the reservoir to flow into the vessel.  
     
     
         35 . The method of  claim 32  or  34  further comprising positioning the adjustable valve system at a third position, prior to positioning it at the second position, wherein the third position disconnects the vacuum, but maintains a homeostatic suction.