When microbiological media has been made, it still has to be sterilized because of microbial contamination from air, glassware, hands, etc. Within a few hours there will be thousands of bacteria reproducing in the media so it has to be sterilized quickly before the microbes start using the nutrients up.
Media for growing bacteria and cells is sterilized before use to prevent the contamination of the desired culture with other types of bacteria or cells. The presence of undesired cells on culture media can lead to the failure of the culture or affect the results of future experiments.
Bacteria and cells are often grown on culture media to determine the presence or absence of specific bacteria or types of cells, such as pathogenic bacteria or abnormal cells that may indicate disease. Cells may also be cultured as part of an experiment to determine if a particular experimental factor has affected the ability of a bacterium or cell to grow. In both cases, the presence of microorganisms other than those that are intended for culture in the culture medium may cause the culture to fail, as the undesired bacteria or cells can out-compete the desired cells for the nutrients in the culture medium.
Answer: This second verb is always in the infinitive form and is placed at the end of the clause or sentence, e.g. Kannst du mir helfen? (Can you help me?)
Explanation:The modal verbs are almost always used with another verb, which is required to complete the meaning.
