Juvenile No Acid Bone & Cartilage Stain
Optimized for 21 dpf zebrafish juveniles but it works well on other similarly sized fish.
Protocol
- Anesthetize fish with MESAB (tricaine) in tubes, fill to top with no airspace and capped, lay tubes on their sides until all gill movement stops.
- Fix: 2% PFA 3 hrs @ room temperature and gently rock on horizontal rotator.
- Wash: Tris/MgCl230 min or more on rotator
- Stain: 0.02% Alcian Blue/10mM MgCl2, pH 7.5; overnight @ room temperature on rotator
- Differentiate/ Re-hydrate:
80% EtOH/100mM Tris, pH7.5/10mM MgCl2; 30 min or more on rotator
50% EtOH/100mM Tris, pH7.5; 30 min or more on rotator
25% EtOH/100mM Tris, pH7.5; 30 min or more on rotator
0.5% KOH; 30 min or more on rotator
- Bleach: 3% H2O2/ 0.1% KOH 30 minutes exact; uncapped, upright tubes
- Rinse: 35% Sat. NaBO4; 30 min or more on rotator
- Clear/digest: 1% Trypsin in 35% Saturated NaBO4 30 minutes; on horizontal rotator, gently
- Wash: 10% glycerol/0.5% KOH; 30 minutes or more, on rotator, gently
- Stain: 0.01% Alizarin, pH 7.5, overnight @ room temperature, on rotator, gently
- Differentiate: 50% glycerol/0.1% KOH; 1 quick wash, 30 min or more on rotator, gently;
- 2nd wash without agitation overnight or more@ room temperature.
- Store: without agitation (at 4C if possible)
- Long term storage: 70%-100% glycerol (in H2O, not KOH) with a couple of thymol crystals; at room temperature.
NOTE THAT SOME SOLUTIONS ARE DIFFERENT THAN FOR 5-7dpf FISH
SOLUTIONS
2%PFA/1XPBS pH7.5 for 50ml:
12.5ml 8% PFA
5ml 10XPBS
q.s. to 50ml water
10mM Tris pH 7.5/25mM MgCl2
To make 50 mls: 5ml 1M Tris pH 7.5
1.25ml 1 M MgCl2
43.75ml water
0.2% Alcian Blue/90%EtOH Stock:Â Alcian Blue will not readily dissolve in EtOH. Â
To  make 100 mls: Add 0.2g Alcian Blue 8GX powder (Anatech, Ltd. #862) to 11.2ml 50% EtOH. Warm and occasionally swirl. When all is dissolved, add 95%EtOH to 100 ml. Check clarity of solution under a microscope to make sure there are no precipitates.
0.02% Alcian/25mM MgCl2 Stain pH 7.5
To make 50 mls:
5ml 0.2% Alcian blue (Anatech, Ltd. Cat. # 862) in 90%ETOH
5ml 1M Tris pH 7.5
1.25ml 1M MgCl2
32.6ml 95% ETOH
6.15ml water
Ethanol rehydration:
To make 50 mls:
80% ETOH/25mM MgCl2
42.1ml 95% ETOH
5ml 1 M Tris pH 7.5
1.25ml 1M MgCl2
1.65ml water
50% ETOH:
26.3ml 95% ETOH
5ml 1M Tris pH7.5
18.7ml water
25% ETOH:
13.2ml 95% ETOH
5ml 1M Tris pH 7.5
31.8ml water
0.5% Alizarin Red S Stock: To make 50 mls, add 0.25g Alizarin Red S (JT Baker cat.# A475-03) to 50 ml water.
0.01% Alizarin Stain/10% glycerol/0.5%KOH
To make 50 mls:
1ml 0.5% Alizarin Stock
5ml 100% glycerol
1.25ml 20%KOH
42.75ml water
10% glycerol/0.5%KOH
To make 50mls:
5ml 100% glycerol
1.25ml 20% KOH
43.75ml water
50% glycerol/0.1% KOH
To make 50 mls:
25ml 100% glycerol
250μl 20% KOH
23.75ml water
35% saturated sodium borate
To make 500mls: 8.3 g sodium borate decahydrate
Q.S. to 500ml
Warm solution on hot plate with stirring until fully dissolved. This should take just a few
minutes. Note: a Saturated solution of sodium borate at 20°C is 23.6g/500ml water.
1% Trypsin/35% saturated sodium borate
Make fresh, using Difco Trypsin 250 at 0.1g per 10mls 35% saturated sodium borate.
3% H202/0.1%KOH:
Make ahead of time and keep at 4C. Bring to room temperature before using to reduce bubbles trapped in fish.
For 50mls:
5ml 30%H202
250μl 20%KOH
44.75ml water
MESAB
Tricaine: 3-amino benzoic acid ethyl ester (SIGMA Cat # A-5040 or FINQUEL, Argent Laboratories #C-FINQ-UE-5G).
Mix in fish safe container with a stir bar:
400 mg tricaine powder
800 mg Na2HPO4(anhydrous)
100 ml glass distilled water
Adjust to ~pH 7 with a drop at a time of 1N NaOH or 1N HCl if needed but it’s
usually the right pH if you weigh the sodium phosphate carefully and measure the water with a graduated cylinder.
8% PFA
8 g Pelleted PFA (Ted Pella, Inc.; cat# 18501)
90 ml dH2O
25 drops 1N NaOH
Heat at very low heat and stir just until solution clears. Q.S. to 100 ml.
Filter and store at 4C not more than 1 week.
Modified from:
A two-color acid-free cartilage and bone stain
for zebrafish larvae
MB Walker & CB Kimmel
Biotechnic & Histochemistry 2007, 82(1): 23-28