3.1 Principle of programming3.2 Ready to use Fraction collector with the supplied tube racks3.3 Programming the OMNICOLL for any tube racks or recipients3.4 Control Panel of OMNICOLL Fraction Collector3.5 Fraction collection according to the volume3.6 Calibration of the peristaltic pump and the OMNICOLL3.7 Fraction collection with a time interval in-between fractions (“high”)3.8 Multi-channel fraction collection – multiple stream sampling3.9 How to increase the capacity of the fraction collector?
Laboratory practice shows that programming of instruments equipped with microprocessors are not simple and mistakes are easily made, especially when such instruments are used occasionally.
We have developed a new method, which should eliminate such problems and make the programming easy for all types of tube racks.
The white lines should be about 2 mm broad and full-length. These lines are detected by the photodetectors of the OMNICOLL fraction collector and the fraction collector stops at these positions. The actual fraction position is about 1 mm after the first edge of the white lines.
The beginning and end signals (at Figure 3.1-3) determine at the same time the position of the first and the last fraction in the row. The fraction position is about 2 mm after the first edge of the white line of the beginning and end stripes.
The magnetic coding bands programmed with white lines for the desired tube racks are provided with the OMNICOLL Fraction collector.
Place the magnetic coding strip strictly horizontally into the corresponding X-axis slot!
Otherwise, the optical detectors could be damaged.
Measure the distance between the tube centres of the desired rack and choose the number of fractions in a row.
Measure the distance between rows. When several tube racks are used, pay attention to difference in distance between the last row of the first rack and the first row of the second rack.
If the fraction collection should be stopped at the last row, then make the last line broader (approximately 1 cm thick). This functions as the stop signal.
Since the coding band is kept in place by magnetic force, it can be easily positioned.
The first row line of the Y-axis should be ca 10 cm from the front.
The LAMBDA OMNICOLL fraction collector-sampler allows the following operation modes:
The fractions are collected from the left to the right. After the last fraction of the row, the collecting arm moves to the left to the first position of the next row.
In the row mode, the position of the fraction collecting arm can be adjusted by using the STEP button.
The time resolution of the OMNICOLL fraction collector can be selected in the following way:
This function allows increasing considerably (by 60 times) the volume of fractions either using a drop counter (art. no. 6926) or motor impulsions counter (counts).
The divider can be set either to divide by one or divide by 60. In the first setting, every drop and every impulsion of motor are counted. In the second setting, sixty drops or impulsions give just one signal.
The volume of fractions can be also varied by the selection of tubing of internal diameters from 0.5 to 4 mm, when constant volume fractions are collected by counting pump impulsions (in “COUN” operation mode – COUNT LED is on, refer section 3.5)
When the OMNICOLL fraction collector and sampler has been equipped with the optional RS-232 interface, it can be controlled digitally, e.g. from a PC.
If you use the OMNICOLL fraction collector together with LAMBDA peristaltic pumps PRECIFLOW, MULTIFLOW, HIFLOW, MAXIFLOW or MEGAFLOW, you can take fractions of precise volume (from 0.05 to 500 ml or 0.6 to 30 litres per fraction).
The heart of these pumps is a stepping motor or BLDC motor, controlled by a generator of electric impulses (microprocessor). After each impulse, the pump motor moves by one step. This movement displaces a very small and precise volume of liquid.
The collector counts these impulses and thus makes it possible to deliver an exact volume of liquid for each fraction. This method is an attractive alternative to the old drop counting procedure, where the volume is affected by the viscosity, surface tension etc. of the respective liquid.
Since the diameter of the tubing used in the peristaltic pumps affects the speed of the flow (flow rate), the pump has to be calibrated before use in order to establish the relation between the count number and the delivered liquid volume.
It is also possible to synchronize OMNICOLL fraction collector with third-party multi-channel or single channel peristaltic pumps (e.g.: Cole parmer, Ismatec, Flexicon, etc.). We can offer customized remote control cable and communication module for pump switching and RS-232 connection (Art. No.: 6911) for the desired peristaltic pump connection.
The LAMBDA peristaltic pump is connected to the OMNICOLL fraction collector via the remote control cable (Art. No. 4810-s) and the communication module box (Art. No. 6911 or Art. No. 6929). The plug-in power supply is also connected to this connection box. (It is impossible to make a wrong connection because the connectors will not fit to the wrong sockets).
Measure the volume of this fraction. This volume corresponds to the pre-set count number.
From this ratio (volume/count number) you can easily calculate the count number corresponding to the desired fraction volume.
LAMBDA OMNICOLL fraction collector and sampler could be used for the collection of samples with a time interval between consecutive fractions varying between 0.1 min and 16.6 hours (999.9 min) or 1 min and 166 hours (9999 min).
This is particularly useful during fermentations and other biological and chemical processes. For this application, switch the microprocessor of the control unit to the “high” mode.
Selecting the high mode:
In the “high” mode you can successively select the parameters TIME, COUNT, PAUSE and NUMBER by pressing the COUNT/TIME button.
After selection of the parameter with the COUNT/TIME button, press the SET button.
After a short beep the name of the parameter will appear during one second, followed by last used value of the parameter.
You can change this value by means of the four buttons Λ Λ Λ Λ under the display. Press the button SET to confirm the new value (long beep).
After setting of the parameters, the fraction collection is started by pressing the START button.
The collector will take the number of samples as programmed under the NUMBER setting and will stop for the time programmed under the PAUSE setting. This cycle will go on until a STOP signal will be encountered. The LAMBDA peristaltic pump is activated automatically only during fraction collection.
Then, the fraction collector will repeat this till the STOP signal is encountered (i.e. STOP is pressed or the fraction collector is stopped by the end magnet). This collection mode allows for e.g. a line washing step before the relevant fraction is taken.
The parameter PAUSE is ignored in this operation mode.
Such a collection mode could be useful for taking of fractions/samples in a process where an alarm situation of a selected process parameter has occurred and the samples can be used for further analysis.
LAMBDA OMNICOLL fraction collector and auto-sampler can be used for all kinds of chromatography such as normal or low pressure chromatography. It is also suitable for medium pressure chromatography sometimes called FPLC (Fast Protein Liquid Chromatography) or high pressure liquid chromatography (HPLC), also referred to as high performance liquid chromatography.
An interesting property of the LAMBDA OMNICOLL fraction collector is the possibility to collect simultaneously the streams of many chromatographic columns.
Multi-stream assembly is available for 2 to 18 or even more effluents of multiple chromatography columns. The multi-channel fraction collection configuration can also be customized for low volume recipients like 96-well plates.
In the number of simultaneous chromatographic streams the OMNICOLL is not outperformed by any other fraction collector on the market.
This multi-stream assembly is technically very simple and polyvalent. It allows an easy adaptation of various experimental needs directly by the user.
For more information about the multiple stream mounting, please do not hesitate to contact us at firstname.lastname@example.org
Since several lower parts of the collector can be coupled together, the capacity of the collector can be increased many times.
The control unit can move freely from one lower unit to the other on the gear rails. Only two rectangular coupling bars are needed to keep two units together.
The tube capacity of the LAMBDA OMNICOLL fraction collector and sampler can be easily increased by the addition of lower support. Virtually any number of capacity extensions can be added.