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Biomedical subjects

E E Geldreich

Publications and source records attributed to E E Geldreich.

5 recordsLinked to original sources
PubMed1979

Rapid seven-hour fecal coliform test.

A rapid 7-h fecal coliform (FC) test for the detection of FC in water has been developed. This membrane filter test utilizes a lightly buffered lactose-based medium (m-7-h FC medium) combined with a sensitive pH indicator system. FC colonies appeared yellow against a light purple background after incubation at 41.5 degrees C for 7 to 7.25 h. Comparison of FC test results showed that the mean verified FC count ratio (7-h FC count/24-h FC count) for surface water samples was 1.08. The mean FC count ratio (7-h FC count/24-h FC count) for unchlorinater wastewater ranged from 1.95 to 5.05. Verification of yellow FC colonies from m-7-h FC medium averaged 97%. Data from field tests on Lake Michigan bathing beach water samples showed that unverified 7-h FC counts averaged 96% of the 24-h FC counts. The 7-h FC test was found to be suitable for the examination of surface waters and unchlorinated sewage and could serve as an emergency test for detection of sewage or fecal contamination of potable water.

Culture Media↗
PubMed1975

Improved membrane filter method for fecal coliform analysis.

A two-layer agar method has been developed which consistently yields higher recovery of fecal coliforms on membrane filters when compared to the existing membrane fecal coliform procedure. This method has been evaluated by three laboratories using samples of raw and chlorinated waste water, and reservoir, river, and marine waters. Verification of 1,013 fecal coliform colonies isolated from 61 water samples averaged 92% on this proposed procedure. Comparison with the Standard Methods membrane fecal coliform procedure revealed the two-layer agar method had an overall increased sensitivity to fecal coliform detection in these waters. It is therefore proposed that this procedure be evaluated as an alternative to the Standard Methods fecal coliform membrane Filter test in the examination of chlorinated secondary effluents, marine waters, and any natural waters that may contain pollutants with heavy metal ions.

Agar↗