English to Spanish Science Genetics Molecules - molecular sensor

An easy one?

"With reference to Figure 1A, there is illustrated a molecular sensor 10 according to the present invention. The sensor 10 comprises a flow path in the form of an elongate pipe 12 that is mostly made from plastic and is opaque. The central portion of the pipe 12 is configured as an observation window 14 and is made from a material that is transparent to the wavelength of light employed. "

"Ventana de observación" simply?!

Thanks!