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Water sampling with Sterivex filter

eDNA Water Sampling Instructions with Sterivex Filter Start here: Watch the Water Sampling Instructional Video

Supplies​

  • Gloves

  • One 50 mL syringe for water sampling

  • One 3 mL syringe for Zymo DNA storage solution

  • One vial of Zymo solution

  • One Luer lock Sterivex filter unit

  • Two Luer lock caps

  • One Whirl-Pac bag

  • Sharpie (not provided)

Instructions​

Below are instructions for collecting your sample that complement the video from above. If you need help, please don’t hesitate to call Julie Stanford at 650-799-7225. 1

Follow the map to your sampling site or choose sites you think would be interesting to sample. 2

Record the site and kit information in the app webform we provided to you in Kobo Forms. Also record backup information on a piece of paper just in case the digital data is corrupted or take screenshots.

Remember:

  • Record the label on the tube.

  • Take GPS Coordinates to a resolution of <50m.

  • If possible, take notes on environmental parameters.

  • Always have a paper backup. 3

Collect the sample.​

First, put on your gloves, using a clean pair for each site.

  • Find an area with low turbidity, i.e. clear water.

  • Remove the Sterivex filter from its sealed package without touching the sterile ends. Write the sample ID on the filter with a Sharpie marker if there no preprinted label, and return the filter to its package.

  • Remove the 50 mL syringe from its container. To rinse the syringe, draw up 50 mL of water from the sampling location, then dispose of that water in the same location. You’re now ready to begin sampling eDNA!

Filtering:

  • Using the syringe, draw up 50 mL of water from the sampling location.

  • Screw the Sterivex filter onto the end of the 50 mL syringe until firmly in place.

  • Gently flush your water sample through the filter to discard the water. Repeat this as many times as possible until the filter is at capacity (stops pushing water through).

  • Record the total amount of water filtered directly on your metadata form and with a sharpie on the filter case. Take a screenshot of the digital form and/or write down the information as a backup.

  • Draw up 50 mL of air, then flush the filter of any remaining water. It's ok if there’s a small amount of water left in the filter.

  • Using the 3 mL syringe, draw up 2.5 - 3 mL of Zymo solution.

  • Then, remove the Sterivex filter from the 50 mL syringe. Screw the 3 mL syringe onto the inlet end of the Sterivex filter and fill the filter completely with the Zymo solution.

After filtering:

  • Seal the filter by adding the Luer lock cap to the outlet end of the Sterivex filter. Remove the 3 mL syringe and add another Luer lock cap to the other end of the Sterivex filter.

  • Place the sealed Sterivex filter into the provided Whirl-Pac bag, and write the sample ID on the bag with Sharpie. You’ve completed sampling water eDNA! 4

Take one photo that you think best captures the ecosystem you sampled in and upload.

Record any additional notes or observations that you think might be relevant (e.g. you forgot to put your gloves on, dropped the top of the tube, the tube fell in a pond, the site had poison oak, you saw a bear, squirrel, fish, etc.). 5

List any species that you see and know on the webform. You can also take photos of them and look them up in iNaturalist (a great app/site for identifying species in photos) and/or add the photos in the web form.

When done sampling - how to preserve and mail samples:​

Please keep the samples in the fridge or at room temperature, out of direct sunlight. Send the eDNA kit to us as soon as possible so that the eDNA doesn’t degrade.

  • Tape the box(es) up securely

  • Drop them in a mailbox with postage or take them to your local post office or use UPS or FedEx to mail them back.

Ship to​

CALeDNA, attn: Rachel Meyer

Coastal Biology Building, UCSC​

130 McAllister Way rm 143

Santa Cruz, CA 95060​

Source document: Google Doc