Multiplex

Multiplex is a multiparametric handheld fluorometer dedicated to the measurement on fruits and leaves. By the mean of 4 excitation and 3 detection wavelengths, the Multiplex sensor measures 9 fluorescence signals.

The sensor has been designed by and for Plant Sciences researchers. Therefore, in addition to the fluorescence signals, Multiplex also gives plant physiological indices linked to chlorophyll, flavonols and anthocyanins content in leaves and fruits.

Multiplex sensor

Portable Fluorometer

Fluorometer

MULTIPLEX is a portable fluorometer. The sensor has 4 excitation channels (UV, blue, green and red) and 3 emission channels (detectors) so it can measure 9 raw fluorescence signals. 

Dedicated to Plant Sciences

Since 2008, Multiplex is mainly used by plant scientists. In addition of the 9 raw fluorescence signals, MULTIPLEX calculates several plant physiological indices such as chlorophyll, flavonols, anthocyanins and NBIs(*).

It’s interesting to measure these compounds as they have multiples roles in the plant.

(*) The principle of measurement of NBIs in Multiplex is not comparable with the NBI measurement in Dualex (learn more).

Multiplex fluorescence signals

Plant physiological indices

Chlorophyll, flavonols and anthocyanins content in leaves and fruits

Multiplex has been designed for plant compounds measurement. In fact, excitation and emission wavelenghts have been choosen in order to calculate some plant physiological indices.

In other words, based on the raw fluorescence signals, Multiplex calculates plant physiological indices like chlorophyll, flavonols, anthocyanins. It could be really useful for abiotic stress studies, but also fruit maturity and quality.

Multiplex also provide NBIs which is known as a good indicator of plant nitrogen statut.

Specificity of Multiplex 330 : blue fluorescing compounds measurement

The  Multiplex can be declined in a specific version named Multiplex 330.

In the Multiplex 330 the UV LED excitation at 365 nm is replaced by a specific one at 335 nm. This allows the Multiplex to detect some specific blue fluorescing compounds in addition to chlorophyll and anthocyanins.

For example the blue fluorescence signal is a good indicator of phytoalexins content in grapevine leaf (resveratrol content), induced by downy mildew on grapevine.

Features

Non-destructive measurement

Flashing with Multiplex doesn’t cause any damage to the material measured. 

Fast and simple 

One measurement takes less than 1 second.

Practical

Multiplex is not sensitive to ambient light so you can use it in lab, in greenhouse or in the field.

Moreover, its processor and its internal memory as well as its real-time display make it totally autonomous (no computer is required).

Polyvalent

Multiplex has 3 configurations (to avoid low signal or saturation) and  3 diaphragms (area of measurement) so it can be adapted to the sample.

Principle of measurement

Chlorophyll measurement

Multiplex measures the chlorophyll content thanks to a ratio of chlorophyll fluorescence. Chlorophyll fluorescence is measured in the far-red (2). Then, it is compared to the chlorophyll fluorescence measured in the red (5), whatever the excitation in the visible.

Because of the overlapping of the absorption and the fluorescence emission spectrum of chlorophyll, reabsorption occurs at shorter wavelengths (red) but not at longer (far-red) wavelengths.

Flavonols and anthocyanins measurement

Multiplex measures far-red chlorophyll fluorescence (2) under a first reference excitation light (1) not absorbed by polyphenols.

Then, Multiplex measures far-red chlorophyll fluorescence under a second excitation light specific to a particular type of polyphenols. For example, green (3) for anthocyanins or UV-A (4) for flavonols.

Due to the polyphenols absorption, only a fraction of this light reaches the chlorophyll in the mesophyll and can generate far-red chlorophyll fluorescence.

Multiplex calculates flavonols and anthocyanins relative content  thanks to a differential ratio of chlorophyll fluorescence.

The principle is named the screening effect of polyphenols on chlorophyll fluorescence.

Publications

Multiplex is mainly used in Plant Sciences research (physiology, agronomy, ecology, …). For example, Multiplex is used for biotic and abiotic stress studies (light, nitrogen, temperature, salinity…), fruit and food quality.

Learn more about Multiplex applications on the link below.