Rapid thermal cycling for sample analyses and processing

Abstract

Method and apparatus for thermal processing of nucleic acid in a thermal profile is provided. The method employs at least a first bath and a second bath, the method further employing a reactor holder for holding reactor(s) accommodating reaction material containing the nucleic acid. The method comprises maintaining bath mediums in the baths at two different temperatures; and alternately allowing the reactor(s) to be in the two baths in a plurality of thermal cycles to alternately attain a predetermined high target temperature THT, and a predetermined low target temperature TLT, wherein the bath medium in at least one of the baths is a high thermal conductivity powder.

1 . Method for thermal processing of nucleic acid in a thermal profile, the method employing at least a first bath and a second bath, the method further employing a reactor holder for holding reactor(s) accommodating reaction material containing the nucleic acid and the reactor(s) being in any form such as tubes or wellplates or chips or cartridges, the method comprising:
 maintaining bath mediums in the baths at two different temperatures; and   alternately allowing the reactor(s) to be in the two baths in a plurality of thermal cycles to alternately attain:
 a predetermined high target temperature T HT , and 
 a predetermined low target temperature T LT , 
   
       wherein the bath medium in at least one of the baths is a high thermal conductivity powder. 
     
     
         2 . The method according to  claim 1  further comprise:
 maintaining the T HT  in the region 85-99 degree Celsius for denaturation of the nucleic acid; and 
 maintaining the T LT  in the region 45-75 degree Celsius for annealing of primers or probes onto nucleic acid or for primer extension, 
 the first and the second baths being for thermal cycling the reactor(s) to attain polymerase chain reaction (PCR) amplification or primer extension. 
 
     
     
         3 . The method according to  claim 2  further employing a third bath, the method comprising:
 allowing the reactor(s) to be in the third bath to attain a predetermined medium target temperature T MT  corresponding to the extension of primers in nucleic acid or the annealing of primers or probes onto nucleic acid. 
 
     
     
         4 . (canceled) 
     
     
         5 . The method according to  claim 1  further employing a fourth bath, the method comprising:
 before the thermal cycling, allowing the reactor(s) to be in the fourth bath for an additional process from the group consisting: 
 a) reverse transcription-polymerase chain reaction (RT-PCR), 
 b) hot start process, and 
 c) isothermal amplification reaction. 
 
     
     
         6 . (canceled) 
     
     
         7 . The method according to  claim 1  further comprising:
 during the thermal cycling, allowing the reactor(s) to be in an air zone for conducting fluorescence imaging or electrochemical detection of the nucleic acid. 
 
     
     
         8 . (canceled) 
     
     
         9 . The method according to  claim 1  wherein the high thermal conductivity powder is metal powder or metal powder dispersed in a liquid. 
     
     
         10 . (canceled) 
     
     
         11 . The method according to  claim 9  wherein the powder comprises metal particles of substantially spherical shape. 
     
     
         12 . The method according to  claim 11  wherein the powder is copper powder of particle size: 1 μm-5 mm. 
     
     
         13 . (canceled) 
     
     
         14 . (canceled) 
     
     
         15 . The method according to  claim 1  further comprising:
 employing a reactor guard to partially confine the reactor(s) to prevent the reactor(s) from getting deformed under resistive forces of the bath medium and the T HT  when the reactor(s) is/are received in the powder. 
 
     
     
         16 . The method according to  claim 1  further comprising:
 attaining the target temperatures by a temperature guided motion controlling means (TeGMCM) that is operable based on the real-time temperature as sensed by a reactor temperature sensor during thermal cycling. 
 
     
     
         17 . The method according to  claim 1  further comprising:
 attaining the target temperatures by a time guided motion controlling means (TiGMCM) that is operable based on the time-periods for which the reactor(s) are allowed to be in the baths. 
 
     
     
         18 . (canceled) 
     
     
         19 . The method according to  claim 1  further comprising:
 calibrating a transfer means to initiate lift-off of the reactor(s) from the bath(s) when the reactor(s) reach a first lift-off temperature that is lower than the T HT  and a second lift-off temperature that is higher than the T LT , in order to compensate for operational electro-mechanical delays that unwantedly cause over heating or over cooling of the reactor(s). 
 
     
     
         20 . Apparatus for thermal processing of nucleic acid in a thermal profile, the apparatus employing a reactor holder for holding reactor(s) to accommodate reaction material containing nucleic acid and the reactor(s) being in any form such as tube(s) or wellplate(s) or chip(s) or cartridge(s), the apparatus comprising:
 a first bath;   a second bath, bath mediums in the baths being respectively maintainable at two different temperatures, and   a transfer means for allowing the reactor(s) to be in the two baths in a plurality of thermal cycles to alternately attain:   a predetermined high target temperature T HT , and   a predetermined low target temperature T LT ; and   an amount of high thermal conductivity powder to serve as the bath medium in at least one of the baths.   
     
     
         21 . (canceled) 
     
     
         22 . (canceled) 
     
     
         23 . (canceled) 
     
     
         24 . The apparatus according to  claim 20  further comprising:
 a third bath wherein the transfer means allows the reactor to attain a predetermined medium target temperature T MT  during the thermal cycling of the reactor(s), wherein the T MT  corresponds to the extension of primers in nucleic acid or the annealing of primers or probes onto nucleic acid 
 
     
     
         25 . (canceled) 
     
     
         26 . The apparatus according to  claim 20  further comprising:
 a fourth bath wherein before the thermal cycling the transfer means allows the reactor(s) to attain a temperature T AP  for an additional process from the group consisting 
 a) reverse transcription-polymerase chain reaction (RT-PCR), 
 b) hot start process, and 
 c) isothermal amplification reaction. 
 
     
     
         27 . (canceled) 
     
     
         28 . The apparatus according to  claim 20  further comprising:
 an air zone wherein the transfer means places the reactor(s) for conducting fluorescence imaging or electrochemical detection of the nucleic acid during the thermal cycling. 
 
     
     
         29 . (canceled) 
     
     
         30 . The apparatus according to  claim 20  wherein the powder is metal powder or metal powder dispersable in a liquid. 
     
     
         31 . (canceled) 
     
     
         32 . The apparatus according to  claim 20  wherein the powder comprises metal particles of substantially spherical shape. 
     
     
         33 . The apparatus according to  claim 32  wherein the powder is copper powder of particle size: 1 μm-5 mm. 
     
     
         34 . The apparatus according to  claim 20  wherein the T HT  is in the range 85-99 degree Celsius for denaturation of the nucleic acid and the T LT  is in the range 45-75 degree Celsius for annealing of primers or probes onto nucleic acid or for primer extension for thermal cycling the reactor(s) to attain polymerase chain reaction (PCR) amplification or primer extension. 
     
     
         35 . (canceled) 
     
     
         36 . (canceled) 
     
     
         37 . The apparatus according to  claim 20  further comprising:
 a reactor temperature sensor; and 
 at least one means from the group consisting: 
 a temperature guided motion controlling means (TeGMCM) that is operable based on the real-time temperature as sensed by the reactor temperature sensor during thermal cycling, and 
 a time guided motion controlling means (TiGMCM) that is operable based on the time-periods for which the reactor(s) are allowed to be in the baths, wherein the transfer means is operable by the at least one means. 
 
     
     
         38 . The apparatus according to  claim 37  wherein the TiGMCM can be user calibrated for the time-periods. 
     
     
         39 . The apparatus according to  claim 20  where in use the transfer means can be calibrated to initiate lift-off of the reactor(s) from the bath(s) when the reactor(s) reach a first lift-off temperature that is lower than the T HT  and a second lift-off temperature that is higher than the T LT , in order to compensate for operational electro-mechanical delays that unwantedly cause over heating or over cooling of the reactor(s). 
     
     
         40 . The apparatus according to  claim 20  further comprising:
 shaking means for shaking at least one from the group consisting:
 a) the bath(s), 
 b) the reactor(s), and 
 c) both a) and b), during reactor insertion in the bath(s). 
 
 
     
     
         41 . Reactor guard for the apparatus according to  claim 20 , the reactor guard comprising:
 confining means to partially confine the reactor(s) to prevent the reactor(s) from getting deformed under resistive forces of the bath medium and the T HT  when the reactor(s) is/are received in the bath medium comprising high thermal conductivity powder.   
     
     
         42 . The reactor guard according to  claim 41  being made up of materials comprising metal or glass or high temperature plastics or ceramics. 
     
     
         43 . The reactor guard according to  claim 41  being an extension of the reactor holder. 
     
     
         44 . (canceled)