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Testing 2mL-100mL Aqueous Samples on R-Card® Using Membrane Filter

NO MORE PETRI DISHES to test water or food and beverage samples for E. coli, Enterococcus, or various other microbes with the R-CARD® from Roth Bioscience, LLC. 

There are now 2 different size cards, the original which is 3.5" x 3" that takes 1mL inoculum and the second card 44.5" x 4" that is designed to take up to 3mL inoculum.

For samples that contain high bacterial levels, just add a 1-3 mL inoculum (undiluted or diluted) to the R-CARD® base, drop the top on it, allow to spread, and incubate. Results will be counted and are quantitative. (No reading MPN for an estimated range, and no presence/absence with no actual numbers.)  

For samples that contain very low microbial counts, where a 1-3 mL inoculum is not sufficient to result in statistically reliable results, or a large sample is desired or required, the use of a 47 mm, 0.45 µm micropore filter may be used to filter the sample, and is easily adaptable for use with the 3.5" x 4" size card. Just filter the desired size sample, lift the top card film, and place the filter (right side up) containing the microbes on the R-CARD® bottom, add 1ml sterile water onto the filter and drop the top part onto it.  Allow the water to spread over the filter, incubate appropriately and count the resulting CFUs.

Step by step guide

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