MERHAB Sampling Protocol:
DNA Samples
1. If not already assembled, plumb your sampling system as follows
(see diagram on page 3):
a. Connect the 3 mm tubing to the bottom of the Swinnex and
the 6.5 mm tubing to the top. The 6.5 mm tubing will be
placed into your sample bottle.
b. Connect the open end of the 3 mm tubing to the small tubing
connector.
c. Fit the small tubing connector into the large tubing
connector.
d. Attach the large tubing connector to the tubing connected to
the hand pump.
2. To place a filter a filter in the Swinnex:
a. Unscrew the Swinnex filter holder.
b. With forceps, pick up a new polycarbonate filter (this is the
shimmery white circle, not the blue circle) and place it onto
the grid on the bottom portion of the Swinnex. Try to center
the filter on the grid, this will prevent ripples or tears when
you reconnect the top part of the Swinnex.
c. With the filter on the grid, squeeze the hand pump very
slowly and gently and then let go quickly. This helps to seat
the filter properly.
d. Screw the top portion of the Swinnex onto the bottom.
3. Collect 1 liter of seawater in the large plastic bottle. Fill the bottle all
the way to the top.
4. Place the bottle containing your seawater sample on a stable,
elevated surface.
5. Insert the 6.5 mm tubing into the bottle, making sure that the end of
the tubing reaches the bottom of the bottle.
6. Allow the tubing, Swinnex, and pump to hang over the side of the
bottle. HOLD THE BOTTLE TO PREVENT TIPPING DURING THE
ENTIRE SIPHONING PROCESS!
7. Before starting the siphon, make sure that the valve below the hand
pump is in the open position (it should be parallel with the white
outlet tubing).
8. With the pump well below the height of the bottle, squeeze the bulb
to start the siphon. Again you need to squeeze gently and
slowly and then release quickly. The water will begin to flow out
of the pump.
9. Try to collect all of the water in the 1 liter bottle, including residual
liquid in the tubing, through the Swinnex – you can tilt the bottle and
“vacuum” out the last of the seawater if you need to. Keep filtering
until there is no more liquid flowing from the pump. If you feel that
the water flow has stopped before you have filtered all of the
1
sample you may repeat step 8. Note that the pump always needs
to stay well below the height of the bottle.
10. To remove the filter from the Swinnex:
a. Disconnect the two connectors from each other (not from the
tubing they are connected to).
b. Carefully, unscrew the Swinnex.
c. With forceps, pick up one side of the filter and gently fold it in
half.
Fold filter in half.
Filter will have cells sandwiched between it.
d. Use the forceps to hold the edge of the filter and place it into a 2 mL
sampling tube containing 0.4 mL of sample buffer (see below).
forceps
filter
2 mL screw cap sampling tube
11. Tap the filter down into the liquid in the sample tube. Cap the tube
tightly.
12. With a permanent marker, fill out the appropriate information
(sampling location and date) for each sample on the sticky labels
provided. Stick the label to the sample tube and place the tube in a
zip lock bag.
13. Rinse the sampling equipment (pump, tubing, Swinnex and 1 liter
bottle) with tap water to prevent salt build-up in between samplings.
2
Preserved Samples
1. Use a 125 mL bottle (without Lugol’s Iodine) to collect a water sample.
2. Pour this sample into the bottle containing the small volume of brown
Lugol’s Iodine solution. The sample will turn a yellow-brown color.
3. Cap the bottle and gently invert several times to mix the sample.
4. With a permanent marker, label each bottle with the sticky labels
provided.
5. Cap each bottle tightly and place in a light-proof container, such as a
cardboard box.
3
Sampling System
1 liter bottle
Level, elevated surface
Swinnex, with polycarbonate filter
3 mm tubing
Direction of flow
Small end of tubing connector
Large end of tubing connector
Detailed View of Swinnex:
Filter placed on
grid on bottom
TOP
portion of
Swinnex
12.7 mm tubing
BOTTOM
Valve must be
parallel to drain
opening during
siphoning
4