Ozone control

Ozone control at OGT

All microarray washing and scanning steps are performed in an environment that maintains ozone levels at 1-4ppb.

These steps are critically important for ozone control in the microarray process.

Fluorescent degradation is especially severe if microarrays are exposed to ozone when slides are drying or dry.

Why is ozone control important?

• Ozone is an unstable gas naturally occurring in the earth's upper atmosphere and at ground level
• Ambient air levels vary between 5 and >124 ppb
• Environmental ozone (>5 ppb) can degrade cyanine 5 (Cy5) dye within seconds
• Cyanine 3 (Cy3) dye is much less affected by ozone (>100 ppb)
• Degradation of the Cy5 signal relative to the Cy3 signal in two-colour microarrays adversely reduces the Cy5/Cy3 ratio — resulting in unreliable data.*

* Branham WS, Melvin CD, Han T, et al. Elimination of laboratory ozone leads to a dramatic improvement in the reproducibility of microarray gene expression measurements. BMC Biotechnology 2007;7:8.