Download - Overview of Otolith Thin Slice Method

Overview of Otolith Thin Slice Method

SDAFS Catfish Technical Committee2014 Catfish Aging Workshop

Procedures

1. Remove and dry

2. Set in epoxy resin

3. Thin slice using a slow speed precision saw

4. Mount thin slice to a slide using Cytoseal™

5. View – using a fiber optic light and dissecting scope

List of Items Used For Thin Slice Method-Slow speed precision saw (Isomet 1000) and cutting fluid (Isocut Plus Cutting Fluid)

-Epoxy resin and hardener (West Systems 105 epoxy resin and 207 hardener)

-Ice cube trays

-Disposable plastic cup and spoon

-Microscope slides

-Cytoseal™ 60

-Forceps

-Warm water

-Paper towels

2. Set otolith in epoxy resin

-Mix resin and hardener in a disposable cup-Pour base layer of epoxy and let harden (~4 hours)-Set otoliths in the tray-Cover with a second layer of epoxy resin and let harden (~typically overnight)

2. Set otolith in epoxy resinSet otoliths in resin with posterior edge near the edge of the epoxy resin

Be Consistent! Set all otoliths with the same orientation to be able to make the same, consistent, cut on each otolith.

3. Thin slice w/slow speed precision saw


Align the saw bladeslightly to the right of the core of the otolith

Zero the micrometer, setspeed to 200 , lift chuck counter balance and pushthe blade button


Cut off the posterior end of the otolith

Raise the counter balance, spin the micrometer wheel until .025” appears on the digital readout


Rinse thinslice in warm waterand dry

Repeat process to take a second cut

4. Mount thin slice to a slide using Cytoseal™Apply a drop of Cytoseal™ to theslide, place thin slice on slide and cover with Cytoseal™

Remove air bubbles

Allow to dry ~ 1 hour to viewboth sides of thin slice

5. View

Same technique can be used for many species

Flathead catfish

Striped bass

Largemouth bass

Black crappie

Grass Carp??

Questions