Homogenizing your Tissues
If you’ve never used a homogenizer before, thought about it might be a little intimidating! While there are various methods to go about the process, selecting the right one may not be so obvious. Keep in mind: not every homogenizer can handle all types of tissue. Below is a guide on how to homogenize your tissue.
Before getting to the process, you’ve got to access your needs. As mentioned earlier, not every homogenizer can handle all tissues. While soft tissues such as adipose are easy to homogenize, very fibrous and hard tissue may require an excellent tissue homogenization.
For severe and fibrous homogenization, rotor-stators or bead mills can both do the job. When using a rotor-stator, make sure that the prone has a saw-tooth or bladed end to help shred the tissues apart. Remember, the shear forces alone may not be sufficient. When using bead mills, make sure that you’re using a very thick bead. You can opt to use jagged or irregular shaped beads if they are available.
Ultrasonic tissue homogenizer are not suitable for a hard and fibrous tissue. Very few tissue homogenizers can handle tough tissue such as bone. You can opt to pre-treat the sample to soften it first, or use ultra-powerful homogenizer.
When handling DNA, you might need to use a different homogenization technique than you would for a small molecule. For instance, isolating intact cells or organelles requires special consideration. Analytes such as RNA are too sensitive to heat. The lower the compartment you need to work on, the more difficult the process becomes.
Heat sensitive samples require heat dissipation features – those that can allow direct cooling, or placing your samples on the ice during processing. Fortunately, some bead mills have cooling elements. Of course, such tools come at a higher price. What’s more, extraction of RNA or DNA is a little sensitive – the more vigorous the process, the more shearing one achieves on the sample. Hence, you may need to optimize your protocol to account for whether you need shearing on your example or not.