| abstract |
Methods for accurately mixing two solutions, e.g., buffer and sample solutions, are provided. A method of mixing first and second fluids using first, second, and third chambers includes selecting a fluid mixture r, providing the first chamber with a first cross-sectional area A 1 , providing the third chamber with a second cross-sectional area A 2 , disposing the first fluid in the first chamber, disposing the second fluid in the second chamber, moving a first plunger within the first chamber at a speed S 1 towards a first port to dispense the first solution from the first chamber into the third chamber, and moving a second plunger substantially simultaneously with the first plunger within the third chamber at a speed S 2 away from the second port to dispense the second solution from the second chamber into the third chamber, wherein A 2 S 2 =A 1 S 1 (1+1/r). The sample and buffer can be mixed, in which case, the first, second, and third chambers can be buffer, sample collection, and mixing chambers, and the first and second ports can be buffer and sample ports. The sample and buffer can be equally mixed, in which case, r=1. To effect equal mixing of the sample and buffer, S 1 ≅S 2 and 2A 1 ≅A 2 , or alternatively, A 1 ≅A 2 and 2S 1 ≅S 2 |