Yes, I have just puchased one. Since I work in a laboratory, I have tested the pen aganst two organisms. E.coli and a Proteus species, both commonly found in fecal contaminated water. The test was strickly qualitative, I made a very heavy suspension of the two organisms (way beyond what would be encountered in nature). After the first expouse with the pen, I was still able to culture viable organisms, however, the numbers of organism was significanly reduced. I exposed the solution to a second dose of the UV, this time no viable organisms were recovered. If the claims of the manufacter are valid the pen has a broad spectum of kill. The pen is however expensive.