Patent ID: 9707555
Date: 2017-07-18
CPC Classifications: B01L,C12Q

Claim:
1. A method of extracting microbial cells from a blood containing sample, the method comprising: adding a blood containing sample to a pretreatment vessel, the pretreatment vessel comprising a pretreatment mixture, the pretreatment mixture comprising a blood cell lysis reagent and a hydrophobic cushioning liquid having a density greater than that of the blood containing sample and the blood cell lysis reagent; agitating the contents of the pretreatment vessel; centrifuging the pretreatment vessel such that the cushioning liquid forms a liquid interface below a supernatant, wherein microbial cells from the blood containing sample are removed from suspension and collected adjacent to the liquid interface; withdrawing a substantial quantity of the supernatant without removing the collected microbial cells; agitating the contents of the pretreatment vessel and allowing the cushioning liquid to re-establish the liquid interface below a suspension containing the microbial cells; and extracting a least a portion of the suspension without extracting a substantial portion of the cushioning liquid, thereby obtaining an extracted suspension comprising microbial cells.