Fluidic imaging barrier, collection container and method of using same for separating and imaging components of a sample fluid

A method for separating particles from a sample of matter and concentrating the particles in a predefined area of a collection container, which comprises the steps of:

• mixing in the collection container the sample of matter containing the particles with a flotation solution having a predetermined specific gravity such that the particles are suspended in the flotation solution, the collection container including walls defining an interior cavity for holding the flotation solution having the particles suspended therein;
• adding a barrier-forming fluid to the interior cavity of the collection container such that the barrier-forming fluid resides on top of the flotation solution, the barrier-forming fluid being immiscible with the flotation solution and having a specific gravity which is less than the specific gravity of the flotation solution and specific gravities of the particles suspended in the flotation solution, the barrier-forming fluid being in contact with the flotation solution at an interface between the flotation solution and the barrier-forming fluid, the flotation solution and the immiscible barrier-forming fluid forming a fluidic barrier within the interior cavity of the collection container at the interface between the flotation solution and the barrier-forming fluid;
• and
• centrifuging the collection container holding flotation solution having the particles suspended therein and the barrier-forming fluid within the interior cavity of the collection container so that particles suspended in the flotation solution having specific gravities which are less than the specific gravity of the flotation solution separate therefrom and move in the interior cavity of the collection container to form a concentrated quantity of separated particles accumulating at a location within the interior cavity of the collection container in proximity to the fluidic barrier.