This invention relates to a device for detecting cancer cells. The device includes a light source for generating light (e.g., a light emitting diode), a first optical filter selected from the group consisting of a band pass filter and a long pass filter, a second optical filter (i.e., a band pass filter) disposed between the light source and the first optical filter, and a sample receiver for receiving a sample. The sample receiver is disposed between the first and second optical filters. The first optical filter, the sample receiver, and the second optical filter are aligned so that light emitted from the light source passes sequentially through the second optical filter, the sample receiver, and the first optical filter.