Oil Red O Staining and Measurement of Lipid Droplets (LDs) in Bovine Hepatocyte Cells

To begin, take a previously seated 24 well culture plate and place a glass cover slip in each well. Then add 800 microliters of culture medium containing 10%FBS and DMEM. After adjusting cell concentration.

Incubate it at 37 degrees Celsius and 5%carbon dioxide for 24 hours. Then discard the culture medium and wash the cells with PBS. Suspend the cells in 800 microliters of DMEM induction medium containing BSA.

Dissolve linoleic acid in anhydrous ethanol to prepare a standard solution at a concentration of 100 millimolar per liter. Add linoleic acid in increasing gradient to the plate and repeat it four times. Then incubate the plate at 37 degrees Celsius and 5%carbon dioxide for 24 hours.

At the end of the incubation, remove the culture medium and wash the cells with PBS three times. Fix them with 400 microliters of 4%paraform aldehyde for 20 minutes. Then discard the fixative solution and wash them again.

Incubate the cells with 60%isopropyl alcohol for five minutes then discard it. Add freshly prepared oil red O working solution and discard it after 20 to 30 minutes. Wash the cells with PBS two to five times until the excess dye solution is removed.

Restain the nucleus with 300 microliters of hematoxylin solution for one to two minutes. Then discard the dye solution and wash them again. Remove the glass cover slip from the PBS washed plate and place it with cells facing down on a microscopic slide containing 10 microliters of tablet sealant.

To measure the size and number of LDs, turn on the computer and microscope switch successively and place the slide on the loading platform. Then open the image analysis software. Find the images at low power and drip an appropriate amount of cedar oil on the imaging slide.

Gradually adjust the objective 200x and adjust the field of view until a clear image is found. Then capture images from the desired regions and save them. Randomly, select 60 LDs for each image and measure the diameter.

Export the measurement results into a table to analyze LDs average size and distribution ratio. The stained hepatocyte cultured cells showed different sizes and numbers of LDs. Under the different concentrations of linoleic acid treatment.

The number of LDs per cell was negatively correlated with different concentrations of linoleic acid. The median LD number per cell was 136 for the 100 micromolar per liter linoleic acid treated group and decreased at high concentrations. The average diameter of LDs in the control group was 0.72 micrometers which increased with increasing concentration in the linoleic acid treated group.

A high linoleic acid concentration increased the proportion of large LDs and decreased small LDs.