The most common cause of condensation is unstable temperatures in the environment where the plates are kept during imaging. The imaging system itself is designed to produce as little heat as possible, but fluctuating temperatures in a room or similar is a common cause of condensation and will often be visible in videos generated. This can occlude the samples and make further analysis or evaluation of the results difficult.
Another common cause of condensation formation is a high humidity level inside the plate chamber. Pouring media at exact and low temperatures is a good way to reduce the humidity saturation. Additionally, plates can be dried out in a laminar flow hood for 15-60 minutes before being stored and/or used.
Some organisms, particularly large fungal colonies, can respirate heavily and release humidity onto the lid of the plate they are being cultivated in. In these cases, it might either be the best to simply accommodate the condensation when evaluating the plates.
Lack of contrast
For highly translucent colonies, contrast can be an issue. Using a black tray and the toplight can often help increase the contrast of each colony. Using higher or lower exposure from the light presets may also help in some cases.
For CFU counting of small, translucent colonies, the best solution is to employ the Reshape Image Analysis suite and timelapse videos of the growth on plates. Using image post processing, we can greatly increase the signal captured from the growth of organisms on the plate and either show this as a visual output to the user, or feed into analysis algorithms.
Achieving correct exposure can be tricky when switching between assays, media types and plate formats. When running a new type of plate for the first type, feel free to select multiple light presets at once so you can easily compare the results.
If none of the presets are suitable for your plate type, please reach out to us at firstname.lastname@example.org so we can help you find a solution
Lack of fluorescent signal
The signal to noise ratio during fluorescent imaging is highly dependant on the specific fluorescent proteins being expressed by a particular organism. First of all, make sure to use the black trays to minimize residual light. Make sure to review the Fluoroscence datasheet and examples and review your fluorescent proteins to ensure compatibility. Comparing for example a fluorescent transformant colony with a non-fluorescent one should give a clear differential signal.
The system is not highly sensitive. The output can be used to quantify differences in intensity of the fluorescent signal, but low levels of expression might not be easily detected. If you are having issues achieving the expected level of signal, please reach out to email@example.com and we can help you review the particular application.