This video demonstrates 2-color whole mount in situ hybridization, a method by which the spatial and temporal expression pattern of 2 different genes can be visualized in young chick embryos. This method was originally introduced by David Wilkinson, Domingos Henrique, Phil Ingham and David Ish -Horowicz.
Part 1: Fixing the embryos
Part 2: Prehybridization
Part 3: Hybridize embryos with probes
Part 4: DIG antibody incubation and color reaction
Part 5: FITC antibody incubation and color reaction
Part 6: Fixation and processing
Part 7: Solutions
Hybridization buffer, store at -20°C in Falcon, 50 ml: 25 ml formamide; 3.25 ml (20xSSC); 0.5 ml (0.5M EDTA); 1 ml (10% Tween-20); 2.5 ml (1% SDS); 125 ul (20mg/ml tRNA); 100ul (50 mg/ml heparin).MABT, prepare 100mM maleic acid; pH to 7.5 with NaOH pellets. Add 150mM NaCl and 0.1% Tween-20.
NTMT (made just prior to use), 50 ml: 1ml (5M NaCl); 2.5 ml (2M Tris-HCl pH9.5); 1.25 ml (2M MgCl2); 5 ml (10% Tween-20).
TBST: 0.1M Tris-HCl, 0.15M NaCl, pH 8.45, 0.1% Tween-20.
Part 8: Troubleshooting
Problem | Cause | Remedy |
Embryo is curled up | Insufficient dehydration/rehydration | Maintain 10 mn intervals during successive dehydration/rehydration steps |
There is no probe signal | Probe is degraded RNase contamination in vial | Run probe on 1% Agarose gel Make sure that the entire vial is exposed to Proteinase K solution in step 2 |
Probe is labels cavities of heart an neural tube | Probe is trapped | In step 2, make sure that all cavities are perforated using microdissection knife or microcapillary |
Embryo disintegrated following hybridization (step 3) | Proteinase K step left too long Hybridization temperature is too high | Proteinase K should not be left longer than 1mn (stages 3+ and 4), 2 mn (stage 5 to 7), 3 mn (stage 8-10), 4 mn (stage 11-13) Do not hybridize at To higher than 65 o C |
Part 9: Representative Results
Representative embryos are shown below: (A) Embryo (stage HH7) is labelled with a DIG-Sox probe (blue) and a FITC-delta-1 probe (red). (B) Embryo (stage HH8) is labelled with a DIG-Pax6 probe (blue) and a FITC-Shh probe (red). Nf, neural fold, anp, anterior neural plate, psm, presomitic mesoderm, n, notochord, nt, neural tube). Probe gifts from the laboratories of Drs. C. Tabin, M. Goulding , D. Henrique, and J. Briscoe.
The 2-color whole mount in situ hybridization method is used to determine both spatial and temporal patterns of gene expression, using one or two genes of interest. Applications include assessment of gene expression patterns of novel genes (e.g. 1,2, as well as changes in gene expression following insult (embryonic manipulations 3, beads 4, and electroporation of RNA or DNA constructs 5).
The authors have nothing to disclose.
This work was supported by the Margaret M. Alkek Foundation to RHF.
Material Name | Type | Company | Catalogue Number | Comment |
---|---|---|---|---|
Eggs | Animal | Charles River | Premium Fertile | |
Stereomicroscope | Microscope | Leica Microsystems | MZ9.5 | |
Marsh Automatic Incubator | Tool | Lyon | RX | |
Hybridization Incubator | Tool | Hybaid | Micro-4 | |
Adams Nutator orbital mixer | Tool | Fisher | 14-062 | |
Curved Forceps (1) | Tool | Electron Microscopy Sciences | 72991-4C | |
Fine scissors | Tool | Fine Science Tools | 14161-10 | |
Spoon | Tool | Fine Science Tools | 10370-18 | |
Pasteur Capillary Pipette | Electron Microscopy Sciences | 70950-12 | ||
Microcapillary tube | Sigma | P1049-1PAK | Pull using vertical micropipette puller; blunt end with fine forceps | |
Microdissecting knife | Fine Science Tools | 10056-12 | Use to puncture cavities prior to in situ hybridization | |
Minuten pins 0.2mm diam | Fine Science Tools | 26002-20 | Keep pins together using a magnetic stirrer; | |
Sylgard 184 Silicon Elastomer Curing Agent and Base | Reagent | Dow Corning | 0001986475 | Mix 1 part Curing Agent, 9 parts Base; set O/N at 37C |
Diethylpyrocarbonate (depc) | Reagent | Acros Organics | 10025025 | Add 1ml depc to 1l PBS; shake; autoclave |
16% PFA | Reagent | Electron Microscopy Sciences | 15710 | |
Tween-20 | Reagent | Sigma | P1379-100ML | |
Proteinase K | Sigma | P2308-5MG | Stock at 10 mg/ml in depc-H2O in 10ul aliquots. Store at -20C. | |
Formamide, deionized | Reagent | Ambion | 9342 | |
Yeast tRNA-25 mg | Reagent | Invitrogen | 15401-011 | Stock at 20 mg/ml in depc-H2O in 125ul aliquots. Store at -20C |
Heparin Sodium salt | Reagent | Sigma | H4784-250MG | Stock at 50 mg/ml in depc-H2O in 100ul aliquots. Store at -20C. |
SSC x20 pH5.5 | Reagent | Fisher | PR-V4261 | |
EDTA (0.5M) | PR-V4231 | Fisher | ||
SDS | Reagent | Fisher | BP166-100 | |
Maleic acid | Reagent | Fluka | 63189 | |
Boehringer Blocking Reagent | Reagent | Roche Applied Sciences | 11096176001 | Use at 2% in MABT. To make, heat with MABT for 20 mn at 60C. Can make a stock and store in 1-5 ml aliquots at 20C. |
Heat inactivated sheep serum | Reagent | Jackson Immuno | 013-000-121 | Dissolve in 10 ml H2O; heat 550C, 30 mn. Aliquot at 1ml, -20C. |
Anti-Digoxigenin-AP, Fab fragments | Reagent | Roche Applied Sciences | 11093274910 | |
NBT/BCIP stock solution | Reagent | Roche Applied Sciences | 11681451001 | |
Anti-Fluorescein-AP, Fab fragments | Reagent | Roche Applied Sciences | 11426338910 | |
2M Tris | BP1759-500 | Fisher | ||
Vector Red Alkaline Phosphatase Substrate Kit | Reagent | Vector Laboratories | SK-5100 | |
1,2,3,4-tetrahydronaphthalene | Reagent | Sigma | 429325-100ML | Under hood |