An apparatus for dispensing a predetermined amount of a sample into a fluid. The apparatus comprises a chamber which may be inserted into a cuvette. The chamber comprises a means such as a membrane or filter ball for dispensing a predeterming amount of a sample into a fluid upon contact of said membrane...http://www.google.se/patents/US5112490?utm_source=gb-gplus-sharePatent US5112490 - Sample filtration, separation and dispensing device
