Instrument and method for collecting nucleic acids

Abstract

An instrument and a method for conveniently collecting nucleic acids from a biological nucleic acid-containing sample are provided. A nucleic acid-capturing tip having silica-containing solid phases enclosed therein in such a state as being capable of coming into contact with a liquid, wherein the solid phases have a water-flowing regions and the average interval among solid phases in the water-flowing regions is regulated to 25 μm or less.

1 . A nucleic acid collecting instrument internally having a silica-containing solid phases in such as state as being capable of coming into contact with a liquid, wherein the solid phases have a large number of water-flowing regions and at these water-flowing regions, an average interval among the solid phases is 25 μm or less.  
     
     
         2 . A nucleic acid collecting instrument according to  claim 1 , wherein the solid phases are made of a fibrous substance and the average interval among the fibrous solid phases is 25 μm or less.  
     
     
         3 . A nucleic acid collecting instrument according to  claim 2 , wherein the fibrous solid phases are silica wools.  
     
     
         4 . A nucleic acid collecting instrument according to  claim 3 , wherein the average interval among the silica wools is any of distances ranging from 13 to 21 μm.  
     
     
         5 . A nucleic acid collecting instrument according to  claim 4 , wherein the diameter of the silica wools is any of sizes ranging from 6 to 12 μm.  
     
     
         6 . A nucleic acid collecting instrument according to  claims 2  to  5 , wherein to keep the distance among the fibrous solid phases, the instrument has such a shape that each of the solid phases is sandwiched between blocking members capable of passing a fluid though.  
     
     
         7 . A nucleic acid collecting instrument according to  claim 5 , wherein the material used for the blocking members is sintered silica particles.  
     
     
         8 . A nucleic acid collecting instrument according to  claims 1  to  7 , wherein the nucleic acid collecting instruments are nucleic acid capturing tips.  
     
     
         9 . A nucleic acid collecting method using the nucleic acid collecting tips attached to a device capable of aspirating and discharging a liquid by changing a pressure applied, the nucleic acid collecting tips having silica containing solid phases enclosed therein in such a state that the silica-containing solid phases may come into contact with a liquid phase, the solid phases having the water-flowing regions, wherein at these water-flowing regions, the average interval among the solid phases is 25 μm or less, comprising: 
 a first step (Step 1) for mixing a first reagent for separating the nucleic acids from the samples with the nucleic acid-containing samples to accelerate the separation of nucleic acids;  
 a second a step (Step 2a) for mixing a second reagent with a liquid containing the separated nucleic acids, then aspirating the resultant mixture into the nucleic acid capturing tips by changing the pressure applied, making the mixture into contact with the solid phases, and finally discharging the mixture;  
 a second b step (Step 2b) for aspirating the second reagent into the nucleic acid capturing tips by changing the pressure applied, then making the second reagent into contact with the solid phases, and finally discharging the reagent to clean the solid phases;  
 a third a step (Step 3a) for aspirating a third reagent into the nucleic acid capturing tips by changing the pressure applied, then making the third reagent into contact with the solid phases, and finally discharging the reagent to remove the first reagent and/or the second reagent remaining in the nucleic acid capturing tips;  
 a third b step (Step 3b) for blowing air into the nucleic acid capturing tips to accelerate the removal of the third reagent from the nucleic acid capturing tips;  
 a fourth step (Step 4) for aspirating a fourth reagent into the nucleic acid capturing tips by changing the pressure applied, then making the fourth reagent into contact with the solid phases, and finally discharging the reagent to flush out the remaining third reagent; and  
 a fifth step (Step 5) for aspirating a fifth reagent into the nucleic acid capturing tips by changing the pressure applied, then making the reagent into contact with the solid phases, and finally discharging the reagent to elute the nucleic acids from the solid phases.  
 
     
     
         10 . A nucleic acid capturing method according to  claim 9 , wherein the solid phases are made of a fibrous substance and the average distance among the fibrous solid phases is 25 μm or less.