Isolation of nucleic acids on surfaces

Abstract

New processes and equipment to isolate and purify nucleic acids on surfaces are provided. The invention focuses on processes which use surfaces, for example, porous membranes, on which the nucleic acids are immobilized in a simple manner from the sample containing the nucleic acids and can be released again by way of simple procedural steps, whereby the simple performance of the process according to the invention makes it possible to perform the processes specifically in a fully automatic manner. An additional aspect of the present invention focuses on binding the nucleic acids to an immobile phase, especially to a membrane, in such a way and manner, that they can be released without difficulty during an additional reaction stage from this phase and, if desired, can be used in other applications, such as restriction digestion, RT, PCR or RT-PCR, or in any of the suitable analyses or enzyme reactions mentioned in the disclosure. Special isolation devices are provided that can be used to carry out the processes according to the invention.

1 . An isolation device adapted to the isolation of nucleic acids comprising:
 at least one cylindrical upper part having an upper opening and a bottom opening;   a membrane located at the bottom opening spanning the entire cross-section of the bottom opening;   a bottom part containing an absorbent material; and   a mechanism for connecting the upper and bottom parts, such that, after the connection is made, the membrane is in contact with the absorbent material and, in case the connection is not made, the membrane is not in contact with the absorbent material.   
   
   
       2 . The isolation device according to  claim 1 , wherein the bottom part is a cylinder having the same diameter as the upper part. 
   
   
       3 . The isolation device according to  claim 1 , wherein the mechanism for connecting the upper and bottom parts also permits a spatial separation of the upper and bottom parts. 
   
   
       4 . The isolation device according to  claim 1 , wherein the connection mechanism is a bayonet socket. 
   
   
       5 . The isolation device according to  claim 1 , wherein the connection mechanism is a threaded socket. 
   
   
       6 . The isolation device according to  claim 1 , wherein the mechanism for connecting the upper and bottom parts includes a sliding member, which can be slid between the absorbent material and the membrane, to separate the upper and bottom parts. 
   
   
       7 . The isolation device according to  claim 1 , wherein the connection mechanism has a predetermined breaking point between the upper and bottom part. 
   
   
       8 . The isolation device according  claim 1 , wherein the upper part is a tube, which is suitable for placement in a reaction container holder. 
   
   
       9 . The isolation device according to  claim 1 , wherein the upper and bottom parts form a tube, which is suitable for placement in a reaction container holder. 
   
   
       10 . The isolation device according to  claim 1 , wherein said bottom part is configured to connect with a plurality of upper parts. 
   
   
       11 . The isolation device according to  claim 1 , wherein said membrane is composed of a material selected from the group consisting of cellulose acetate; non-carboxylized, hydrophobic polyvinylidene fluoride; and massive, hydrophobic polytetrafluoroethylene. 
   
   
       12 . The isolation device according to  claim 11  wherein said membrane material is in the form of a granulate. 
   
   
       13 . The isolation device according to  claim 11 , wherein said membrane material is in the form of a fiber. 
   
   
       14 . The isolation device according to  claim 13 , wherein the fibers are organized as a fleece. 
   
   
       15 . The isolation device according to any one of  claims 1  to  14 , wherein the absorbent material is a sponge. 
   
   
       16 . The isolation device according to any one of  claims 1  to  14 , wherein the absorbent material comprises granules. 
   
   
       17 . A method of using an isolation device according to  claim 1  for isolation of nucleic acids comprising:
 charging a nucleic acid-containing fluid sample into the upper part of the isolation device of  claim 1  so that the sample contacts the upper surface of said membrane;   immobilizing the nucleic acids on said membrane; and   contacting said absorbent material with said membrane to draw the fluid parts of the sample through the membrane.   
   
   
       18 . The method of use according to  claim 17 , further comprising the step of:
 analyzing at least one property of said nucleic acids in said isolation device.   
   
   
       19 . The method of use according to  claim 17 , further comprising the step of:
 performing at least one chemical reaction with said nucleic acids in said isolation device.   
   
   
       20 . The method of use according to  claim 19 , wherein said at least one chemical reaction is amplification of said nucleic acids. 
   
   
       21 . An isolation device adapted for the isolation of nucleic acids comprising:
 at least one upper part having an upper opening, a bottom opening, and a membrane which is located at the bottom opening of said upper part and which covers the entire cross-section of said bottom opening;   a bottom part having an absorbent material; and   a collar surrounding the upper part at least in the area of the membrane containing a coolant.   
   
   
       22 . The isolation device according to  claim 21 , wherein said collar has two compartments, which are separated from one another by a frangible separation wall; and wherein each of the compartments contains a solution, wherein mixture of the respective solutions in the two compartments produces a coolant. 
   
   
       23 . A kit for the isolation of nucleic acids comprising:
 an immobilization buffer;   an elution buffer; and   at least one isolation device according to  claim 1 .   
   
   
       24 . The kit according to  claim 23 , further comprising a washing buffer. 
   
   
       25 . The kit according to  claim 23  or  24 , further comprising a lysis buffer.