Cancer cell enrichment system

Abstract

Embodiments of the invention relate to a cell culture incubator having a gas flow regulation system that exerts control over atmospheric parameters within the incubator. Particular embodiments include an enclosed environmental chamber and a control unit operably linked thereto, the control unit having an oxygen module and a pressure module. Control unit embodiments, by way of these modules, are configured to regulate both oxygen partial pressure and total gas pressure within the enclosed environmental chamber. Embodiments of the control unit are adapted (a) to provide instructions to the oxygen module to regulate an oxygen level to an instructed hypoxic oxygen level and (b) to provide instructions to the pressure module to regulate total gas pressure to an instructed positive pressure level. The regulation of oxygen to the instructed hypoxic level prevails despite an oxygen partial pressure-increasing effect of the positive pressure condition associated with the instructed positive pressure level.

1 - 26 . (canceled) 
     
     
         27 . A method of regulating a gas flow system within an enclosed environmental chamber that is within a cell culture incubator comprising:
 providing a gas flow system within the cell culture incubator comprising:
 an oxygen sensor to measure a chamber oxygen level within the enclosed environmental chamber and to convey a sensed oxygen signal; 
 a pressure sensor to measure a total gas pressure within the enclosed environmental chamber and to convey a sensed pressured signal; 
 an air injection pump to provide external atmospheric air to the enclosed environmental chamber; 
 a nitrogen source to provide nitrogen to the enclosed environmental chamber; 
 a vent to release gas from the enclosed environmental chamber; 
 and a control system to receive the sensed oxygen signal from the oxygen sensor, and the sensed pressured signal from the pressure sensor; 
   regulating the chamber oxygen level within the enclosed environmental chamber to a set hypoxic oxygen level that is less than 20.9% oxygen;   regulating the total gas pressure within the enclosed environmental chamber to a set positive pressure level greater than 14.7 PSI; and   maintaining the chamber oxygen level to the set hypoxic oxygen level and the pressure level to the set positive pressure level independently of each other.   
     
     
         28 . The method of claim  1 , wherein regulating the chamber oxygen level further comprises injecting air with the air injection pump into the enclosed environmental chamber when the chamber oxygen level is below the set hypoxic oxygen level. 
     
     
         29 . The method of claim  2 , wherein prior to injecting air, the method further comprises sensing the chamber oxygen level is below the set hypoxic oxygen level with the oxygen sensor. 
     
     
         30 . The method of claim  2 , wherein the chamber oxygen level reaches the hypoxic set oxygen set level as a result of injecting air into the enclosed environmental chamber, and wherein the method further comprises ceasing to inject air. 
     
     
         31 . The method of claim  1 , further comprising permitting a flow of nitrogen into the enclosed environmental chamber by opening a valve connecting the nitrogen source to the enclosed environmental chamber when: (a) the total gas pressure within the enclosed environmental chamber is less than 14.7 PSI, or (b) the chamber oxygen level is above 20.9% oxygen. 
     
     
         32 . The method of claim  5 , wherein, prior to permitting the flow of nitrogen into the enclosed environmental chamber, the method comprises sensing the total gas pressure is below the set positive pressure level with the pressure sensor. 
     
     
         33 . The method of claim  5 , wherein, prior to permitting the flow of nitrogen into the enclosed environmental chamber, the method comprises sensing the chamber oxygen level is above the set hypoxic oxygen level with the oxygen sensor. 
     
     
         34 . The method of claim  5 , wherein permitting the flow of nitrogen into the enclosed environmental chamber occurs when the total gas pressure within the enclosed environmental chamber is less than 14.7 PSI, and when the total gas pressure has reached set positive pressure level, the method further comprises ceasing the flow of nitrogen. 
     
     
         35 . The method of claim  5 , wherein permitting the flow of nitrogen into the enclosed environmental chamber occurs when the chamber oxygen level is above the set hypoxic oxygen level, and when the chamber oxygen level has reached the set hypoxic oxygen level, the method further comprises ceasing the flow of nitrogen. 
     
     
         36 . The method of claim  5 , wherein the set positive pressure level is within a range of about 0.5 PSIG to about 30 PSIG. 
     
     
         37 . The method of claim  5 , wherein the set positive pressure level is within a range of about 1 PSIG to about 20 PSIG. 
     
     
         38 . The method of claim  5 , wherein the set positive pressure level is within a range of about 2 PSIG to about 10 PSIG. 
     
     
         39 . The method of claim  5 , wherein the set positive pressure level is within a range of about 2.5 PSIG to about 5 PSIG. 
     
     
         40 . The method of claim  5 , wherein the set hypoxic oxygen level is within a range of about 0.1% to about 21% oxygen. 
     
     
         41 . The method of claim  5 , wherein the set hypoxic oxygen level is within a range of about 1% to about 12% oxygen. 
     
     
         42 . The method of claim  5 , wherein the set hypoxic oxygen level is within a range of about 2% to about 6% oxygen. 
     
     
         43 . The method of claim  1 , wherein the gas flow system further comprises a carbon dioxide source, and a carbon dioxide sensor to measure the carbon dioxide level within the environmental chamber, the method further comprising permitting a flow of nitrogen into the enclosed environmental chamber when a carbon dioxide level within the environmental chamber is above a set carbon dioxide set level. 
     
     
         44 . The method of claim  1 , further comprising releasing gas through the vent of the enclosed environmental chamber when the total gas pressure within the enclosed environmental chamber is above the set positive pressure level. 
     
     
         45 . The method of claim  18 , wherein when, as a consequence of releasing gas through the vent, the total gas pressure within the enclosed environmental chamber decreases to the set positive pressure level, the method further comprising closing the vent. 
     
     
         46 . The method of claim  1 , wherein regulating the chamber oxygen level to the set hypoxic oxygen level comprises regulating a composition of gases in the enclosed environmental chamber such that (1) when the oxygen sensor senses the chamber oxygen level to be below the set hypoxic oxygen level, regulating the chamber oxygen level comprises injecting air into the enclosed chamber, and (2) when the oxygen sensor senses the chamber oxygen level to be above the set hypoxic oxygen level, regulating the chamber oxygen level comprises injecting nitrogen into the enclosed chamber, wherein both injecting air and injecting nitrogen in response to the sensed oxygen signal occur independently of the sensed pressure signal from the pressure sensor. 
     
     
         47 . The method of claim  1 , wherein regulating the total gas pressure to the set pressure level comprises regulating the total gas pressure such that (1) when the pressure sensor senses the total gas pressure to be below the set positive pressure level, regulating the total gas pressure comprises injecting nitrogen into the enclosed chamber, and (2) when the pressure sensor senses the total gas pressure to be above the set positive pressure level, regulating the total gas pressure comprises releasing gas from the enclosed chamber by way of the vent, wherein both injecting nitrogen and releasing gas occur independently of the sensed oxygen signal from the oxygen sensor.