what is the effect of false-positives and false-negative results in the Colilert Method (ONPG test) and how do these affect the concentration of faecal coliforms in water samples?

what does a false-negative do in the onpg test

Context: Turn the following into a 100 word hypothesis: It is hypothesized that if water samples are collected from sites further away (downstream) from the Eastern Sewage Treatment Plant, then those samples will exhibit higher levels of contamination and thus concentration of faecal coliforms. High levels of precipitation across the South-East of Melbourne could have led to sewage spilling into the adjoining Patterson River and as a result the flow of the river may have carried these contaminants downstream towards the Mouth into Port Phillip Bay. As measured by the ONPG test, if the distance from the sewage plant of where the sample was taken increases, then these samples will exhibit an increase in their absorbance values due to the greater amount of β-galactosidase present and therefore concentration of faecal coliforms. Similarly, in terms of the MPN test, the further away from the treatment plant, the greater the number of pink colonies formed and therefore the concentration of gram-negative lactose fermenting bacteria.

write a hypothesis clearly outlining the independent and dependent variables for the following aim of an experiment: To determine the presence of gram-negative bacteria, i.e. faecal coliforms, in water samples collected at six different sampling sites along the Patterson River, by quantifying the concentration of faecal coliforms through conducting the ONPG Test (Colilert Method) and the Most Probable Number (MPN) Test. Moreover, the attainment of these measures will be compared with permissible governmental standards, known as the EPA guidelines, and suitability for primary and secondary recreation contact recreation evaluated.

explain what the positive and negative results by using the MPN method using macconkey agar to determine faecal coliform concentration?

Select the statement that indicates a "false positive."a.)Testing a shipment of dairy products reveals salmonella when, in fact, the bacteria is not present.b.)A jury concludes that a man is innocent when he is actually guilty.c.)A pregnancy test tells a woman she is not pregnant when, in fact, she is.d.)A control strip fails to indicate a two degree increase in temperature in the storage area.