Do I have a high- or low-profile blade holder?
The easiest way to tell if you have a high- or low-profile blade holder is simply to measure its blade groove. High-profile blades are about 0.5 inches tall, while low-profile blades are 0.25 inches tall. The depth of the groove should tell you what type of holder you have.
Alternatively, you may also have an adjustable blade holder. These holders allow you to add the ledge to accommodate low-profile blades or remove it to use a high-profile blade. You can identify an adjustable blade holder by the two screws holding the ledge on; to remove the ledge, simply take the two screws out and slide the ledge off.
Should I get high- or low-profile blades?
High- and low-profile blades produce roughly equivalent sections, so there's no need to worry about getting whichever one that is better for your samples. You only need to make sure that you're getting a blade that your blade holder will accommodate.
Blades are typically available from your cryostat's manufacturer. Alternatively, you could purchase them from a third-party vendor.
Should I get disposable or permanent blades?
Over time, cryostat manufacturers began favoring disposable blades because they section more cleanly than permanent blades. Nowadays, the majority of cryostats accommodate disposable blades exclusively.
Of course, that's not to say that permanent blades have no place. For labs on a tight budget, buying a few permanent blades and sharpening them regularly will be cheaper in the long run than constantly resupplying disposable blades. Additionally, permanent blades are ideal for remote clinics that may not have constant access to disposable blades.
Do I need automatic disinfection?
Regardless of the samples you're sectioning, regularly disinfecting your cryostat is an absolute necessity. Integrated disinfection systems using fumigation or UV light can make maintenance considerably easier. In general, both research and pathology labs would benefit from an automated solution to supplement their manual disinfection procedures at the very least, but they're not a necessity if your facility's manual disinfection procedure is sufficiently thorough.
What type of automatic disinfection should I use?
There are two main types of automatic disinfection: UV disinfection, and fumigation. Each has distinct advantages and drawbacks.
UV disinfection doesn't pose a safety hazard to the user like fumigation does. It's also very fast; a chamber can be disinfected by a UV system in just a few minutes. However, UV disinfection isn't quite as thorough as fumigation. If any angle of the chamber is shielded from the light, it won't be disinfected.
Fumigation systems disinfect much more deeply than UV systems. The gaseous disinfectant, whether it's O2, peroxide, or something else, expands to fill the chamber completely, thus reaching every nook and cranny that a UV light system would miss. While very effective, disinfection via fumigation is also very time-consuming. The entire process can take several hours, so most users typically run the disinfection protocol overnight.
What temperature is suitable for my application?
The answer to this question is entirely determined by the type of tissue you're sectioning. Here's a helpful reference guide to the temperature ranges suited for different types of tissue.