Detection of amplification product can be determined via photometry for turbidity caused by an increasing quantity of magnesium pyrophosphate precipitate in solution as a byproduct of amplification.[4] This allows easy visualization by the naked eye, especially for larger reaction volumes, or via simple detection approaches for smaller volumes. The reaction can be followed in real-time either by measuring the turbidity[5] or by fluorescence using intercalating dyes such as SYTO 9.[6] Dyes such as SYBR green, can be used to create a visible color change that can be seen with naked eyes without the need for expensive equipment, or a response that can more accurately be measured by instrumentation. Dye molecules intercalate or directly label the DNA, and in turn can be correlated to the number of copies initially present. Hence, LAMP can also be quantitative. In-tube detection of DNA amplification is possible using manganese loaded calcein which starts fluorescing upon complexation of manganese by pyrophosphate during in vitro DNA synthesis.[7]