Q: How much media should I place in the probe?
A: 0.5 to 1ml of media is required.
Q: Is there a special way to prepare media in the probe?
A: No, prepare the media drop the same way as your other dishes. You must ensure the media covers the sensor at the tip of the probe.
Q: When should I place the probe in the incubator?
A: You should place the probe in the incubator with your dishes, at the same time.
Q: How long is the warranty period?
A: Both the pH Meter main unit and probe have 12 months’ warranty.
Q: How quickly does the probe equilibrate?
A: The probe responds quickly, typically less than two seconds. The probe holder is designed to be placed in the incubator and mimic the gas transfer between incubator and media. If it is put into the incubator at the same time as the culture dish it will give a live reading of pH in the culture dish.
Q: Can I use the pH meter to adjust CO2 in my incubator?
A: CO2 levels will influence pH, but the relationship between the two is not a simple one. pH is also influenced by temperature, pressure and medium chemistry1.
1Pool T, (2004). Optimizing pH in clinical embryology. Clinical Embryologist, 7(3), pp.1–17. Available at http://www.clinical-embryologist.com.
Q: How do I calibrate the unit?
A: Use the calibration buffers provided by RI. The full calibration procedure is described in the user manual.
Q: How often does the probe need calibration?
A: Check with pH7.00 buffer daily. If the reading is incorrect then perform a recalibration. Calibration should also be done each time the meter is switched off and back on, whenever a new probe is connected, or whenever the calibration reminder on the meter appears.
Q: How long does a probe last?
A: The probe is relatively robust and should last for at least a year with correct maintenance.
Q: How do I clean my probe?
A: Soak briefly in a lab detergent such as 7X and rinse with purified water. Use the soft bristled brush supplied to clean the probe and rinse again with purified water. Follow this with a soak in potassium chloride solution. See the User Manual for full instructions.
Q: How long can you continuously monitor media pH in an incubator with IVF media and protein, before you have to clean the probe?
A: We currently recommend a maximum recording length of 24 hours. The probes naturally exhibit a small upwards drift in pH. Within 24 hours this drift should be no more than 0.14pH, and will be automatically corrected by the built in Drift Compensation feature.
Q: Does protein affect how often the probe needs to be cleaned and the life of the probe?
A: Proteins tend to adhere to the probe surface, hence higher concentrations will require the unit to be cleaned more regularly.
Q: How can I measure the pH of several incubators in succession?
A: We don’t recommend you measure in succession because each measurement should take 24 hours, and if measurements are done too quickly the accuracy is compromised. We suggest, upon acquiring the pH Meter you measure each incubator in the lab, following the instructions in the manual. When you are satisfied all incubators are working with sufficient uniformity the pH Meter should only be employed when there is a change to the conditions. This means when there is a new batch of media or CO2 a reading can be taken from any of the incubators, and that reading should be representative of all other incubators.