Immunofluorescence- SFTPC, NKX2.1, and ACTA2
Purpose: Immunofluorescence on slides of 7µm frozen sections of C57Bl/6 E18.5 lungs for NKX2.1, SFTPC, and ACTA2 with antigen retrieval.
- Paraffin sections are placed at 60oC for 2 hours to overnight to melt paraffin.
- Paraffin sections are then placed in xylene 3X for 10 minutes each, followed by 3X in 100% ETOH for 3 minutes each, 95% ETOH for 3 minutes each, and 70% ETOH for 3 minutes each. Slides are then placed in 1X PBS for 5 minutes to completely rehydrate tissue.
- Briefly equilibrate slides in Antigen Retrieval Buffer.
- 10 mM sodium citrate, pH 6.0, and heat in a microwave for 15 min at 90oC. *We usually do a series of three runs to equal the time/temp because of evaporation (refill coplin jars with dH2O).
- Microwave according to instructions on microwave.
- Cool on countertop, 15 min.
- Rinse with dH2O
- 1X PBS, 5 min.
- Block in 4% Goat serum/PBS-T, 2 hours at RT.
- For Rabbit anti-SFTPC (RB458, BL 8/24/11, in house) dilute 1:500, for guinea pig anti-NKX2.1 (G237, Bl. 10/7/11) dilute 1:200, for mouse anti- ACTA2 (α Smooth muscle actin, A5228, Sigma) dilute 1:2000 in blocking buffer and incubate on tissue overnight @ 4oC.
- Rinse slides in PBS-T 3X, 5 min.
- Apply secondary antibody, Goat Alexa Fluor 488 anti-rabbit IgG (A11034, Lot# 1298480, for anti-SFTPC), Goat Alexa Fluor 555 anti-guinea pig IgG (A21435, Lot# 1571699, for anti-NKX2.1) at 1:200 at 1:200, Donkey Alexa Fluor 647 anti-mouse IgG (A31571, Lot# 1366514, anti- ACTA2) at 1:200, in blocking buffer. Spin down antibody cocktail in a µfuge for 10 min and incubated at room temperature for 1 hour.
- Rinse in PBS-T 3X, 5 min.
- Dilute DAPI 1:2000 and apply to slides for 10 min.
- Wash in PBS-T 3X, 5 min.
- Rinse slides in 0.1M PB or TB, 3X, 5 min.
- Add 1 drop of Prolong Gold anti-fade mounting medium (P36930).
- Coverslip with Gold Seal Coverslip (Cat# 3422 Electron Microscopy Sciences, 22 X 22 mm).
- Allow Prolong Gold to cure overnight at room temp in light sealed box.
Crown-to-Rump Length: 21.0 mm
Antigen Retrieval Solution
18ml Solution A- 0.1M Citric Acid (Sigma, C1909) pH 2.5
82ml Reagent B- 0.1M Sodium Citrate (Sigma, S4641 ) pH 8.2