Apparatus for dilution of liquid specimens

An apparatus for dilution of liquid specimens which comprises in combination, a tubular chamber having cap members disposed at opposite ends thereof, a cylindrical member projecting from one of said cap members, said cylindrical member having a restricted opening at one end for receiving fluids, a spring biased piston slidably disposed within the cylindrical member, means for limiting the movement of said spring biased piston out of the cylindrical member, a second piston axially disposed through a bore within the spring biased piston, said second piston having substantially the same length as the spring biased piston, a piston rod projecting through the opposite cap member and engaging the second piston by means of a head portion, said piston rod having externally disposed means for movement of the spring biased piston and the second piston respectively whereby controlled amounts of a liquid specimen may be introduced into the cylindrical member upon retraction of the spring biased piston, and further controlled amounts of a liquid specimen may be introduced into the cylindrical member upon retraction of the second piston.