Aurora Scientific FAQ
Smooth muscle strips or vessels (i.e. bladder, stomach, colon, vaginal, aorta) can be measured either in a vertical (1200A) tissue bath with a larger volume of solution (10mL-100mL, 1 or 2 samples) or horizontal (1500A) tissue bath with a smaller volume (2mL; 1 sample). The horizontal system is microscope mountable for simultaneous imaging and mechanics. Generally speaking, the types of mechanics measurements being performed would help determine the proper system.
When it comes to measuring engineered constructs, whether it sheets, rings or other 3D scaffolds, the 1500A system is best suited as it provides the greatest flexibility in terms of force range, volume and microscope mounting capabilities for imaging and sarcomere length measurements.
The dual-mode lever and high-speed length controller boxes are matched to a specific motor model, thus using two different motor models is not possible with a single controller. 300C/300C-LR lever systems work with model 6350 motors, 305C-305C-LR lever systems work with model 6650-LR motors, 310C/310C-LR lever sustems work with model 6400 motors. 315C/D length controllers work with model 6215H motors and 322C/D length controllers work with model 6220H motors. However, two of the same motor model works with a matched controller box (i.e. Two 300C motors (6350) works with a single 300C lever system controller).
The coverslip on the bottom of an 801C, 802D, 803B, 804A or 470A apparatus is a standard coverslip that is attached using vacuum grease. These can be replaced with extra coverslips located in the accessory box along with a syringe filled with vacuum grease.
The mechanical stimulator includes seven 3D printed tips with diameters of 0.3, 0.5, 0.8, 1.0, 1.5, 2.0 and 3.0 mm. These and extension tubes are also sold separately.
The 400 series transducers are capacitance based transducers and are linear in both compression and tension. For use in compression, the sensor head should be positioned with the capillary tube vertical and perpendicular to the tissue of interest. Often the sensor head is mounted to a manual or motorized translational stage to move the sensor into position and control application force.
The 300C-I mechanical stimulator can be used to study pain (nociception) or touch (somatosensation) in a number of different preparations incuding skin-nerve, tongue-nerve, immobile paw or hand and head fixed animals for brain or meningeal studies (i.e. TBI, Migraine, etc.)
If the transducer or software is not to blame, then check that the LED pulses light blinks when the unit has the range set to something other than off and the adjust dial above 0. Press the manual trigger button and the pulse light should blink, if so then it is likely the unit is outputting some current or voltage.
Another cause for no force is that the unit is overheating due to continual use and thus the FET(s) inside the box is temporarily shut off with the internal thermal regulation circuit. Open the box, allow to cool and try again the next day to see if the unit is working normally. If not, toggle the pulses switch to negative, positive and bi-phase to see if the output changes at all. It’s possible one or both FETs is blown is the output varies or does not happen in these positions. If this is the case then reach out to technical support.
First check that the unit is turned on and that the sensor cable is plugged in properly. Once these obvious causes are eliminated, check to see if the voltage display on the controller is changing when the sample is contracting or when lightly touching the output tube. If the answer is yes, then the unit is detecting force and you can refer to the software FAQ (600A or 615A) if you are not detecting the force change in software.
If the amount of force being registered is much less than normal, then there could be some mechanical impedance between the transducer hook/tube and other parts of the system. If the output tube or hook has recently been replaced, then inspect inside the sensor head for possible epoxy or glue under the flexure or broken flexure. Sometimes if too much epoxy or glue is applied it can flow underneath the glass/flexure and thus the flexure becomes stuck and unable to measure force. If the flexure is broken or glue is under it then it will need to be sent back for a flexure repair. If not, inspect the output tube to ensure it is properly secured. If this is loose it will not transmit some or all of the tension put on it by the tissue preparation so it will need to be replaced.
Ensure the motor is properly connected to the controller. If so, check that the inhibit switch located on the dual-mode lever controller is set to run and not stop, stop indicates current is not going to the motor. Should the motor still not have resistance, ensure the force offset dial is set to 10 (or all the way CW) and is in isometric mode. If the above does not resolve the issue, contact technical support for further assistance.
The 400 series transducers have an overload circuit built in that elicits a beep if it experiences a load larger than it is rated to. Remove or reduce the load on the transducer. If the load has been removed and the beeping is still continuous then the transducer is overloaded somehow and most commonly this is from the pin/hook/tube touching something. Move the transducer up and away from any physical barrier or contact and see whether the beeping stops.
If the beeping persists then another potential cause could be some foreign material (such as glue) around the output tube after installing a new hook/pin with the tube vertical which could have flowed to this area and dried up causing the tube to be ‘stuck’ and thus overloaded. Inspect this area for any noticeable impedement.
If a tube repair has recently been performed, then it is possible too much epoxy has been applied and some of it has flowed underneath the glass/flexure and dried which causes the flexure to be stuck to the substrate body and manifest itself as an overload, lack of force response or a slow response altogether. By inspecting this area you can determine if the flexure is stuck or broken.
The 220A olfactometer is designed to deliver a single odor at a time with a repeatable profile.
Due to the modular nature, the 220A can be configured with 4, 8, 12 or 16 total odor vials.
The Olfactometer Mass Flow Controllers are rated between 5 and 30psig of air pressure, whether that be from a compressor or tank. However, for optimal performance, we suggest keeping the pressure above 20psi.
Check to ensure the final valve is securely connected to the port underneath the mixing valve. If so, confirm the ethernet connection is active and the software and NI drivers have been installed correctly prior to opening the software control program.
If the odor profile is not consistent or shows peaks and valleys during the plateau region, then it is likely the odor stabilization delay needs to be adjusted as the mixing of odorant has not sufficiently occurred. Increasing the delay time allows for the odorant and dilution flow to mix properly prior to reaching the final valve to ensure consistent odor profile delivery.
First check that DIO1 mode is configured properly. In the configure system window of the 220A olfactometer control software, ‘sequence start trig’ should be selected. If so, then the problem is likely from the sequencer window where the user must check the box ‘use DIO1 as sequence start trigger.’ For control of individual odorant release within a sequence, the user must select ‘ext trig’ as the delay to challenge to trigger each line of the sequence externally. In addition, you wish for the odorant duration to also be externally controlled, the user should select ‘falling edge’ which indicates the final valve will be closed when the unit sees the falling edge of a TTL pulse.
external triggering of the final valve (release of odorant to animal) can be done directly using the front panel BNC connection labelled “Final Valve Trg In.”
If this occurs, please check your windows settings to ensure that the computer is using decimal separators and not a comma. This is predominately seen in users within continental Europe.
This could occur when the lamp has not been lit in a long time or it is nearing the end of life. In these instances, our auto lighting circuit may not always catch and turn on the lamp. One means of testing whether the lamp is still functional, or whether the RF circuit is viable, is to light the lamp manually. To do so, turn on the unit like normal, and then remove the circular cap which holds the lamp in the sensor head. You will need to disconnect the suction line at the head, but the cable should otherwise remain connected. You can then slowly pull the lamp partially in and out of the holder until it begins to glow violet. If the lamp lights simply replace the cap and use the unit as normal. We can light the lamp in this manual way as we alter the electric field around the lamp when we pull it in and out. Because the action of altering the field by hand occurs far more slowly than with the automatic circuit, there is no virtually no risk of it not catching on if it is actually viable.
In short, yes you can. The miniPID is calibrated for propylene initially and can always be used to measure relative concentration, by far the most common means. However, to measure absolute concentration you will need to calibrate your miniPID unit using known concentrations of your odorant or by mixing pure odor with clean air using a rotometer or mass flow controller system. Alternatively, you can use an odor with the same ionization potential as your odor of interest in the same manner.
First, ensure the lamp is lit. If so, check to see if the baseline signal is saturated at +/-10V which would indicate an electrometer issue requiring technical support. If the signal is not saturated and the lamp is lit, attempt to generate a signal using the cap of a sharpie pen which would elicit a strong signal response. If there still remains no response, check all tubing and wire connections for any disconnect prior to contacting technical support.
If the output is lower than usual, the lamp itself could be dirty and coated with residual odorant. Remove the lamp from the sensor head and clean it with methanol using a Kim-wipe and let dry. Often a dirty lamp can show a higher baseline. Should the output remain low, the lamp run voltage can be adjusted to increase the brightness of the lamp. Shoulder neither of these resolve the problem, a new lamp may be required.
This likely means the ‘zero’ needs to be adjusted and thus the odorant being measured has a lower signal than the clean air source being used resulting in what appears to be a negative signal. To adjust the zero for your clean air reference, turn the PID unit on like normal and connect the inlet needle of the PID directly to your clean air supply with the offset knob at 5 on the front panel. Measure the output of the PID directly with a voltmeter or some similar tool. As with the lamp brightness adjustment we should open the miniPID controller and adjust the Zero potentiometer labelled R39. Just as is done at the factory we should ensure that the output of the PID is set to 0.1V for their clean air reference
Products manufactured by Aurora Scientific Inc. (ASI) are guaranteed to the original purchaser for a period of three (3) years and a performance guarantee of 90 days. For more details, visit our terms and conditions.
If there is no force being recorded by the unit, make sure the inhibit switch on the controller is in the run position. If it is in run, then check to see if the force offset dial is at 10. If the unit is at 0 then it’s likely there will be no force recorded without a force control command in the software. If neither of these apply, check to see if there is a voltage change on the force display of the controller when you press on the lever arm/footplate. If not, then it is possible the motor is broken. To check this, substitute a 2nd motor of the same type and if the problem is not resolved then the motor may be require repair or replacement, contact technical support. Should the voltage change on the controller but not software then the dual-mode lever is likely working but there may be some issue with the connection to the software or with the software itself, in that case refer to the DMC FAQ.
Linux controlled systems include a license for a single computer. DMC/DMA LabBook software suite (615A) includes a single license for DMC and 2 licenses for DMA-HT. Additional licenses can be purchased.
Any system that is controlled with DMC/DMA requires a PC or laptop with WIndows 10, 4GB+ RAM, 500GB+ Hard Drive and a full width PCI express slot for PC only.
Check that the BNC connections are made correctly between the dual-mode and the 604A or associated interface. Then, ensure the ribbon cable or USB cable connecting the interface to the PC or laptop is connected properly. If you have a PCI card, check to see if this is seated properly in the slot, or move it to another slot if available.
If the connections have been made correctly, ocate and open the NI Max program on your PC. Click on devices and interfaces on the main screen, this should indicate which DAQ devices are present/installed and working. It should show the model of the DAQ being used and there should be an icon that is green showing it is working. If there are multiple devices on there (i.e., Dev 1, Dev 2) and only one is working then it is likely that there was a second device accidentally installed by Windows and DMC is communicating with the wrong one. Go to DMC-File-Open Log Folder and delete the file DAQdevice.ddv. Re-open DMC, select the device that is working (i.e. Dev 2). Then ‘remember my selection’ and OK. Check to see if the communication is now restored via live data monitor. This can more commonly occur when frequently connecting and disconnecting a USB DAQ device.
The license file is saved in C:ProgramDataDMCSUITE which is a hidden folder. To view this folder you must be able to view hidden files & folders. If the user that is logged into the PC does not have full control of this folder (full read/write access), then you will not be able to properly write the license file to this folder. To set full control, navigate to the folder, right click on it and select permissions and then change the permissions to full control under the security tab. You will likely need to delete the .ini file that is presently in this folder as it may not overwrite properly even once the folder permissions have been altered.
Note that there are other folders in Program Data associated with the DMC/DMA suite and it is recommend the user change the permissions on these folders as well.
Skeletal muscle mechanics can be measured with any of our systems, 1200A/1205A, 1300A/1305A, 1400A, 1500A, 1600A, 1700A. The main determinant for which system is best suited would be the muscle preparation being used. For whole muscle (i.e. EDL, SOL, Diaphragm strips) or whole animal, 1200A/1205A, 1300A/1305A and 1500A (isolated whole muscle or engineered constructs) can be used. For fiber/small bundle mechanics, the 1400A (permeabilized or intact) or 1500A (intact) would be recommended. If you’re looking to measure from permeabilized cells the 1600A is best and for single myofibrils our 1700A system is used.
Cardiac muscle mechanics can be measured in a number of our systems including the 1400A, 1500A, 1600A, 1700A. Determining which system best fits your needs revolves around the type of preparation being used. For strips (i.e. heart wall), bundles (i.e. trabeculae, papillary) or engineered constructs the 1500A system would be best suited. When it comes to single fiber mechanics the 1400A (permeabilized and intact) or 1500A (intact) would be recommended. Should single permeabilized cardiomyocytes be of interest then our 1600A system is best suited or for single myofibrils our 1700A.