Refrix - Refractive Index Measurement

Refrix is a software for measuring, recording and analyzing changes in refractive index of liquids.
This measurement is obtained using an ultrasensitive physical principle known as surface plasmon resonance (SPR). The system measures the surface plasmon resonance (SPR) with a special biosensor (Spreeta). During the measuring of biomolecular interactions, the software continuously records an displays the refractive index calculated from actual resonance-point data. Furthermore, the system receives and shows the data of the connected temperature sensor too.

During the measurement the user can make comments placed on the curve. In addition, user can may define automatically-placed comments, in which case, if the change of refractive index is exceeding the preset threshold, the software automatically places a marker at the given position.
On special chart-displays, user can monitoring the raw (primary) signal transmitted by sensor and the derived averaged curve continuously. For the help of resonance-point calculation, trigger-level (baseline) can be set on the averaged curve.
The resonance point-detection on the primary curve made by special Bézier Curve Fit Method. This provides a highly accurate tracking of the curve changes.
Filter is also assignable to the calculated refractive index curve, with freely adjustable period-number (1..60). Software provides opportunity simultaneous opening of up to four previously recorded curves. In this case, the curves can be moved relative to each other and the minor differences between the curves also can be observed.
To evaluate measurements a movable data-cursor is available, which can be moved on the refractive index curve. During the moving of the cursor, the averaged curve is immediately displayed on the Averaged Sample display with the originally calculated resonance point state.


Before taking any measurements or after exchange of biosensor, calibration of the system must be implemented. User must load the corrective data of biosensor (determined by the manufacturer) and must load one data-series which is measured with a clean and dry surfaced sensor. Here should be determine the refractive index value, which is used as a reference. Here can be specify the sampling rate and set the averaging time, wich latter forms filtered signal from the raw data.


Before taking measurements it is possible to change the hardware settings of the basic functioning of biosensor.
Here can be set, inter alia, the integration time, LED intensity and temperature too.

Both the hardware and the calibration settings are can be saved so later can be open the desired file and the system is immediately ready for measurement.