This post highlights two simple tools I made to make tissue staining faster. I was driven to create these devices after I had to drain and fill over 1000 wells one by one. The tissue staining these tools are used for are of 300 micron thick coronal sections of embryonic mouse brains that are stored in 24-well plates.
Vacuum Suction Tool
The vacuum suction device can drain 4 wells of a 24-well plate at the same time. These plates are used for many things such as cell culture and tissue staining. Draining the wells of the plate one by one is quite laborious and so this make-shift device greatly reduces the time spent. Disposable pipette tips are placed over the ends of 6″ glass pasteur pipettes to help keep the device clean, vacuum suction keeps the tips on (though as you will see halfway through the video, a small piece of agarose clogged one tip and this caused a loss of suction which led to a tip coming off ).
The technique shown in the video is important in avoiding damage to the tissue and a description of it follows. The plate is held at an angle and the suction device drains fluid from the highest side of the wells. Gravity helps keep the tissue from floating towards the pipette tips. Next the plate is slowly brought level again and the rest of the fluid is removed. Since the level of the fluid is reduced before the plate is brought level, most tissue samples will not be able to be pulled towards the pipette – thus reducing the risk of damage.
How to make one
Materials: 6″ glass pipettes, 3/8″ vinyl tubing, 1/4″ vinyl tubing, hot-glue gun and hot-glue sticks, aquarium air-splitter( I do not know the real name for these), and an attachment substrate (I used the lids of Ikea brand plastic containers, though anything really should work).
How: Use a 24-well plate as a guide to mark the substrate with a pen. This is how you will establish the proper spacing for the pipettes. Once you have the spacing marked, apply a few drops of hot glue and attach each glass pipette one after the other. At this point the small amount of glue will be strong enough for you to check the spacing but not strong enough for active use. Once you know the pipettes are spaced evenly horizontally and vertically add copious amounts of glue around and between the pipettes and then finish by adding a second substrate to the top (such that each substrate is like sandwich bread between some meat).
Cut four 1.5″ pieces of 3/8″ tubing and attach these on the ends of each glass pipette. Next cut four 6″ pieces of 1/4″ tubing and then attach one end of these tubes to the aquarium-air splitter and push the other end of the tubes inside the 3/8″ tubing that is fixed to the pipettes. Attach the aquarium air-splitter to whichever vacuum line you typically use for draining samples.
Well Filling Tool
When you have over a thousand wells that need to be quickly filled with solution the use of a 3mL plastic pipette simply sucks. Originally I started using 50mL syringes because I did not have to refill them as often as the 3mL pipettes. But as my mind wandered during the mindless filling of countless wells I decided I wanted a way to fill more than one at a time. I had tubing and drip-system fittings laying around and so I decided to build something.
While I failed in my goal was to make something that filled all 24-wells at once, I did succeed at multiplying the number of wells that could be filled. Ultimately the humongous size of the drip-system fittings prevented me from making a robust filling system because the spacing needed exceeded the size of the 24-well plate.
How to make one
Materials: 50mL syringe, 1/4″ tubing, 1/4″ drip system fittings (1 “T” intersection” and two right angle turn pieces), razor blade
How: Some of the tips of the 1/4″ drip system fittings need to be truncated in order for them to align with the plate’s wells. Cut the tips off the fittings as indicated by the red “*” in the figure below. Use 1/4″ vinyl tubing to attach the fittings together with the tubes as indicated by the placement of blue lines in the figure below. Lastly, use 1/4″ vinyl tubing to connect the fittings to the 50mL syringe, the placement is indicated by the green line in the figure below.
Note: The right angle turn fittings will directly touch the T-intersection piece – the tubing merely holds them together.