Tissue Collection Protocol
Organize your Materials
Label your Tubes
Collect Tissue
Tissue Collection Video
Tissue Collection Protocol
By now you should have taken pictures of the mushroom in the field, collected the mushroom, and brought it back for preservation. Your field data slip should be filled out, providing your specimen with a unique collection number. (This is the preferred method but it is also acceptable to use the iNaturalist or Mushroom Observer observation number for labeling tubes and voucher specimens.) Your specimen should be cracker dry. We will now take a small piece of tissue from the mushroom and preserve it in a very small plastic tube: a 1.5 microliter (mL) microcentrifuge tube, also called an Eppendorf tube, or "eppi tube" for short.
NOTE: Sequencing technology and procedures continually change! Originally we used tubes with a buffer solution. Now we are putting dried tissue into empty eppi tubes. And for a while our labs wanted a small piece of specimen in a resealable bag, called a split sample, sent with the eppi tubes. We are no longer asking for splits -- although they might increase changes of success for old or degraded material. If you were sent small plastic bags along with your tubes, you can ignore them.
Lay your mushroom sample out on a clean table. Wipe off any organic matter and sterilize the tweezers with an alcohol swab and lighter. The primary goal with the flame is to burn off the alcohol, rather than getting the tweezers red-hot between each sample. A quick wipe with a swab and a very brief flame (2-3 seconds) is sufficient.
Tweeze off a small portion of mushroom tissue that is about the size of a grain of rice. It is possible to take dried tissue from any part of the mushroom in order to acquire DNA. For larger specimens, we typically suggest samples to be taken from the gills, pores or other spore-bearing surface. For small samples, we recommend taking tissue from the stem of the mushroom as to preserve as much of the cap as possible. The cap contains many more parts that could be important for future microscopic study. Thus, we want to maintain as much of it as possible intact.
Place this piece of material into your eppi tube and close the cover. Ensure that the tube is properly labeled with your collection number (field slip, iNat or MO). If you are using NAMP field slips, cut off the small number in the lower right of the slip, trim the number with scissors to remove excess border, and tape it towards the top of the label with clear scotch tape. Leave the bottom of the tube uncovered so the sample is visible. That is all that needs to be done for this sample. Insert it into the box with dividers, keeping the samples in numerical order. Repeat this process for your next sample.