How to Handle Floating SK-BR-3 Cells?

SK-BR-3 [SKBR3] cells (human breast adenocarcinoma cells) were isolated in 1970 by Trempe G. and Old L. J. from the pleural effusion of a 43-year-old Caucasian female with breast cancer. These cells are known to overexpress the HER2/c-erb-2 gene.

When culturing SK-BR-3 cells, one of the most common challenges is cell detachment or floating. SK-BR-3 cells tend to recover slowly from cryopreservation, and they may not adhere well during the thawing process. This is a normal phenomenon. During the first week of culture and after each passage, SK-BR-3 cells may exhibit loose attachment or floating cells.

Key Recommendations for Handling Floating SK-BR-3 Cells

• Avoid Disturbing the Cells During the First Few Days Post-Thaw

If a significant amount of floating cells is observed, particularly in the first week of culture, it is best to minimize any disturbances to the cells during the initial recovery phase. After receiving the cells, passage them based on their density, and refrain from handling them for at least 3 days after passaging (as long as the medium does not show significant color changes). As the cells recover, they typically exhibit good spreading and attachment (see Figure 2 for reference).

• Assess Cell Viability Using Trypan Blue

If floating cells persist, perform a viability check using Trypan Blue staining. Collect the floating cells by gentle centrifugation, retain them, and reintroduce them into the same culture vessel along with the adherent cells during medium changes. Avoid discarding or separating the floating cells.

• Expect Initial Clusters and Gradual Adhesion

Initially, cells may attach as small patches?or clusters, and many cell aggregates?may remain in suspension. After a few days, cells will begin to adhere and spread out. Some cell debris may also be observed, which can be removed during medium changes.

Notes and Best Practices for SK-BR-3 Cell Culture

1. Retain Floating Cells

Always collect floating cells by?gentle centrifugation (125 ×g for 5-7 min) and return them to the culture vessel during medium changes or passaging.

2. Avoid Overgrowth and Premature Trypsinization

SK-BR-3 cells tend to form aggregates. Avoid trypsinizing the cells until they reach 70-80% confluence. Overgrowth can lead to cell detachment and excessive floating.

3. Optimal Passaging Schedule

SK-BR-3 cells should be passaged approximately once per week. If the cell density is low, perform a 1:1 split onto a fresh plate after one week of growth. This can help improve?cell morphology and attachment.

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By following these guidelines, you can effectively manage the floating issue and ensure healthy, consistent growth of SK-BR-3 cells in culture.