This test is subject to several sources of interference of luminescence including loss of bacteria from effects other than toxicity such as filtration of the sample; absorption of light due to color; and scattering of light due to turbidity.[16] Corrections can be made by testing a sample of similar particle composition that is known to not be toxic. This test consists of two controls and 13 sample dilutions in duplicate.[16] The Solid-Phase Test exposes the bacteria in such a way that is not always possible with pore water and elutriate.[2]