Cultivation of Anaerobic Microorganisms Using Anaerocult®
For the cultivation of facultative or obligate anaerobic microorganisms, Merck provides the Anaerocult® incubation system, covering the products Anaerocult® A, Anaerocult® A Mini, Anaerocult® P, Anaerocult® IS and Anaerotest®. The importance of anaerobes as pathogenic agents responsible for infectious diseases and the role they play in the microbial spoilage of food and water has been better appreciated over the years. Very different spectra of anaerobic organisms are relevant to the food and beverage industries on the one hand and in clinical microbiology on the other. Anaerocult® products from Merck cover a wide range of requirements for cultivating anaerobic microorganisms:
Anaerocult® A is used for anaerobic incubation of up to 12 petri dishes in an anaerobic jar. This reagent contains components which create an oxygen-free (anaerobic) environment in the jar and simultaneously release CO2. The contained oxygen does not react with hydrogen to H2O but is chemically bound to the finely distributed iron powder in the reagent mixture. The reagent is packed into little plastic shells which are sealed with special paper. The paper ensures rapid, unobstructed diffusion of evaporated water and of atmospheric oxygen into the reagent mixture as well as the release of carbon dioxide into the anaerobic jar. This results in a reduction of the oxygen concentration and higher CO2 levels. No further steps are required and no additional reagents or auxiliaries needed.
Anaerocult® A Mini
Anaerocult® A Mini is used for the anaerobic incubation of one to four petri dishes. The Anaerocult® A Mini sachet is moistened with water and placed, together with the petri dishes and an Anaerotest® Strip to monitor the absence of oxygen, into a special incubation bag. Anaerocult® A Mini contains components which chemically bind the oxygen quickly and completely, creating an oxygen-free and CO2-containing atmosphere within the bag.
Anaerocult® P is used for anaerobic incubation of individual petri dishes. The Anaerocult® P sachet is moistened with water and placed in a special incubation bag, which is subsequently sealed. It contains components which chemically bind the contained oxygen quickly and completely, creating an oxygen-free environment and CO2-containing atmosphere. The transparent incubation bag allows anaerobic growth in the closed anaerobic system to be evaluated visually at any given time; the cultivated plates are never exposed to atmospheric oxygen. Each petri dish can be incubated immediately after receiving the sample; Anaerocult® P is thus ideal both for urgent cases (emergencies) and for cultivating extremely oxygen-sensitive microorganisms. Incubation of individual petri dishes permits each one to be cultivated separately over the time period and at the temperature required. It also prevents interactions between the microorganisms on different plates.
Anaerocult® IS is a gas generator system for the anaerobic incubation of identification systems and susceptibility tests. It contains components that chemically bind any oxygen present in very little time while releasing carbon dioxide, thereby creating an anaerobic atmosphere. The special incubation bag is designed to accommodate all identification galleries currently on the market. Each item for incubation can be evaluated without disrupting the anaerobic conditions. Results that are initially unclear can be checked repeatedly without having to open the incubation bag.
Anaerotest® is a test strip for checking whether the atmosphere in sealed containers or special incubation bags is anaerobic. The reaction zone of the test strip contains a dye that is blue (oxidized state) if in an air-filled (i.e. aerobic) environment. An anaerobic environment causes the chemical reduction of the dye, which then changes its color to white. The reaction is reversible so that when oxygen is re-introduced, the reaction zone turns blue again. The strips do not change color when used with Anaerocult® C and C Mini due to the residual oxygen content in the atmosphere of the bags. Anaerotest® is therefore unsuitable for use with Anaerocult® C and C Mini.