Fixing, staining, and storing three-spined sticklebacks
Fixing
Use a lethal dose of MS-222. Rinse fish with water. Place in jar of 10% formalin (=3.7% formaldehyde). Fix for two weeks.
Rinsing (1)
Strain formalin into receptacle. Rinse fish in water for 24 hours. Dispose of the formalin safely (see the
Disposal of dangerous chemicals page).
Staining
1% KOH = 1 gram/100 ml water to which you add enough Alazarin Red powder to turn the solution Purple ("Welch's Grape Juice" colour). Pour rinse water through strainer, replace with Alazarin Red solution. Stain for 24 hours (depending on size of fish, etc.).
Rinsing (2)
Strain KOH solution into receptacle. Rinse fish well with water, up to 24 hours. This will usually clear away any stain picked up by non-bony tissues. Dispose of the KOH solution safely (see the Disposal of dangerous chemicals page).
Storing
Store rinsed fish in 40% isopropyl alcohol. We usually get our isopropyl alcohol from the fish museum. To get more, call the assistant at (604) 822-4803 (currently Katriina Ilves, katriina105@shaw.ca).
Conclusions
Fish are now ready to be measured or kept in storage. If they are going to be in storage for a long time, it is recommended that you check fluid levels in jars every 6 months or so.