【Aladdin】3T3-L1 Adipocyte Differentiation Protocol

Licia Miller   Product Manager

3T3-L1 cells are a cell line isolated from mouse embryonic fibroblasts that have the ability to differentiate from rapidly dividing preadipocytes into adipocytes.

It was first isolated from mouse embryos by Green, Kehinde and others in 1974. Due to its ability to differentiate into adipocytes in vitro, this cell line is widely used to study adipocyte differentiation, metabolism, and the pathogenesis of metabolic diseases such as obesity and diabetes.

There are many ways to detect the induction effect. Among them, Oil Red O staining is a classic method for detecting the accumulation of fat droplets in adipocytes, which can be used to visually evaluate the degree of cell fatification. Oil Red O is a fat-soluble dye that can specifically bind to neutral lipids in cells to form red lipid droplets. The formation of lipid droplets can be observed under a microscope. When the number and size of lipid droplets increase, it indicates that the induced differentiation is successful.

In addition, the induction effect can also be judged by molecular marker detection, such as by detecting the expression of adipocyte-specific genes or proteins to evaluate the degree of cell differentiation. Commonly used gene markers include PPARγ (peroxisome proliferator-activated receptor γ), aP2 (adipocyte fatty acid binding protein), LPL (lipoprotein lipase), etc. Or the protein expression level corresponding to the gene can be detected by Western Blot. In addition, the morphology of 3T3-L1 cells after induced differentiation will change significantly, and a large number of lipid droplets will appear in the cells. This morphological change can also be used as a preliminary basis for judging whether the induction is successful.

This article uses a six-well plate as an example to introduce the experimental protocol for differentiating 3T3-L1 cells into adipoid cells.

Stage 1    Cell Culture

Seed the cells at a density of 3 × 103 cells per cm2 in a six-well plate.

Notice:

(1) It is recommended to use early passage cells for experiments to ensure the differentiation effect.

(2) The cells should be spread evenly. Uneven spreading may lead to uneven differentiation, low differentiation ratio, and cell floating during differentiation.

2. Grow cells in DMEM until they reach 70% confluence and change the medium every 2 to 3 days.

3T3-L1 cells are usually cultured in DMEM high-glucose medium with 10% calf serum or fetal bovine serum added to promote cell growth. When the cells grow in an incubator (37°C, 5% CO₂) to a confluence of about 90%, differentiation induction can be performed.

The confluence before differentiation should not exceed 70%, otherwise it will increase cell death after differentiation.

Notice:

(1)Using medium with high serum content can promote fat accumulation.

(2)Cell density is a key factor affecting differentiation results. Too high or too low confluence will affect differentiation efficiency.

Stage 2    Preparation of Differentiation Induction Medium

Media preparation must be performed under sterile conditions in a tissue culture incubator. MDI (methylisobutylxanthine, dexamethasone, insulin) induction medium and insulin medium should be prepared freshly.

Experimental Steps

1. Prepare stock solution.

Prepare stock solutions of IBMX (50 mM) and dexamethasone (1 mM) in DMSO. If using lyophilized insulin, reconstitute according to the manufacturer's instructions.

2. Prepare 100 mL of MDI induction differentiation medium.

3. Prepare insulin culture medium.

Insulin was added to DMEM to a final concentration of 10 µg/mL.

Phase 3​   Differentiation of 3T3-L1 cells into adipocyte-like cells

Experimental Steps

1. Remove the cell culture plate from the incubator, remove the DMEM medium, and add 2 - 3 mL of MDI induction medium to each well ( marked as day 0).

Notice:

(1) When adding inducers to 3T3-L1 cells, the technique should be particularly gentle. When adding liquid, try to let the pipette tip add slowly along the side wall to reduce the impact on the cells and prevent the cells from curling up.

(2) The induction medium needs to be preheated to 37°C before use to reduce stimulation to the cells.

2. On day 3, remove the MDI induction medium from the cells and replace it with 2-3 mL of insulin medium.

3. On day 6, remove the insulin medium and add fresh DMEM.

4. Generally, fully differentiated adipocytes can be obtained by the 7th to 10th day.

5. Differentiation effect detection. Differentiation into adipocyte-like cells can be tracked by Oil Red O staining to monitor lipid accumulation, or by monitoring the expression of adipocyte markers such as adiponectin and FABP4.

Note: Saturated Oil Red O staining solution is not easy to stain, and the Oil Red O staining solution needs to be diluted according to the instructions before staining.

For more product details, please visit Aladdin Scientific website.

https://www.aladdinsci.com/