RAMOS® (Respiration Activity MOnitoring System) developed by Hitech-Zang is the measuring system for the online determination of the breathing activity of prokaryotic and eukaryotic cultures in shake flasks
The respiration rate is directly proportional to the aerobic metabolic activity of living cells and thus allows a continuous monitoring of the cell growth and, indirectly, of the product formation rate.
Through the use of RAMOS® in screening for efficient production strains and optimum process control, amortization may be achieved in a short time through savings in labor-hours and the shortening of development times, leading to a sustainable and decisive reduction in production costs.
Ø More information on your microbiological processes
Ø Differentiation of process-based and biological effects
Ø Replaces expensive tests in a fermenter
Ø Culture conditions identical to standard shake flask
Ø Virtual non-stop operation thanks to short set-up times and simple handling
Ø Ensures optimal screening conditions
Ø Fast and specific media optimization
Ø Reduction of the effective test duration
Ø Shortened "time to market"
Ø Production strain screening
Ø Process optimisation
Ø Media optimisation
Ø Fermentation validation
Ø Scale-up
By default, investigations to determine the breathing activity in stirred tank reactors are carried out by separate exhaust gas analysis. Statistically reliable results, however, demand many parallel tests which considerably increase the amount of experimental effort required. By using RAMOS® eight tests may be carried out during the same period in parallel and recorded online, thus making the amount of time and costs only a fraction of that of conventional methods.
Media optimization is a typical screening application with a correspondingly high number of experiments. Due to the considerable experimental effort in general complete or complex media (e.g. LB medium for E. coli) are used for the cultivation. The heterogeneous composition of complex media often leads to limitations in growth of product formation, as one or more substances are stoichiometrically or simply insufficiently available. Using the combination of RAMOS® with statistical experimental technique (DOE - Design Of Experiments), the influence of each substance on growth and product formation can be determined in a very short time.
Basic biological phenomena can be easily detected with the aid of the measurement curves, examples being:
Ø Substrate/oxygen limitation
Ø Product inhibition
Ø Diauxia
Ø Fermentation
Ø Overflow metabolism
Key insights were obtained in this way during a number of tested processes, thus giving decisive impetus for many years of development work.
Ø Continuous monitoring of the growth of prokaryotic and eukaryotic
Ø cultures including that of mammalian cells
Ø Eightfold parallel online measurement of breathing activity under sterile conditions
Ø Easy determination of typical characteristics (OTR, CTR, RQ, μ max )
Ø Bioprocess optimisation through the early recognition of oxygen and substrate limitation or product inhibition
Ø Bioassays (toxicity test, proliferation assay)
Ø Determination of suitable operating parameters for primary and secondary screening (media, test duration, operating conditions)
Ø Reduction of the development times for media and process optimisation
Ø Process balancing and quantification
Ø Quality control
The oxygen transfer rate (OTR) is the most suitable and most universally measured variable for the characterization and quantification of the physiological condition and the activity of a culture of aerobic micro-organisms, because almost every metabolic activity is coupled to oxygen consumption.
The online-measurement of the OTR in stirred bioreactors is nowadays state-of-the-art technology but is technically rather complex.
The determination of the OTR has, on the other hand, not been possible until now under sterile conditions in shaken bioreactors (shake flasks). RAMOS® fills this gap and combines the advantages of a shake flask (low space requirement, inexpensive, can be parallelized etc.) with those of the stirred bioreactor (online-measurement technology).
Measurement of Carbon Dioxide Transfer Rate
In addition to the OTR, the carbon dioxide transfer rate (CTR) and respiration quotient (RQ) are important sources of information for micro-biologists and cell-biologists.
The CTR (in the case of RAMOS® the "gas development rate") enables the additional use in many cases of RAMOS® for anaerobic and micro aerophilic organisms.
Using the RQ permits us to detect, among other things, which type of nutrient source of the microorganisms should be assimilated, for example
Ø RQ(Glucose) = 1
Ø RQ(triglycerides/lipids) = 0,65
The RAMOS® shake flask system was developed in cooperation with the Faculty for Bioprocess Engineering at the RWTH Aachen. The demand for equivalent culture conditions for microorganisms in regular shake flasks and in RAMOS® flasks was the top priority in the development of the system. For this reason, the volumetric flask was designed in such a way that in the lower liquid-filled section it matches a standard stirred flask in terms of gas and hydrodynamics.
Furthermore, a method was developed which makes it possible to determine the oxygen transfer rate solely from the change in the oxygen partial pressure in the gas section of the volumetric flask (no invasive electrodes). The system is protected by patent.
The gas composition above the culture liquid in the measuring system flasks is set identically to that of a normal flask in order to ensure equivalent culture conditions.
The handling of the system is simple and can be quickly learnt. After only a short time, like numerous users before you, you will not be able to imagine working without RAMOS®.
The RAMOS® system fits on a standard benchtop. It is supplied fully assembled with a shaker, incubator, control PC, USV and software.
