What to do if the results do not fully meet the criteria?

1. Low Cell Viability (< 80%)

• Recommended solution: Use flow cytometry or the Miltenyi Dead Cell Removal Kit to enrich viable cells.
• Suggested input: 500,000 viable cells (minimum 100,000 if the sample is not enough).
• Common causes: Typically observed in necrotic or damaged tissue samples, or in tumors after drug treatment.
• Optimization tips: If the viability is between 80–85%, resuspend the pellet in 4 mL of RPMI-1640 medium supplemented with 10% FBS, mix gently, and centrifuge once more to wash the cells.

2. Low Nucleated Cell Ratio (< 55%)

• Recommended solution: Use flow cytometry or the Miltenyi Debris Removal Kit for sample cleanup.
• Suggested input: 500,000 viable cells (minimum 100,000 if the sample is not enough).
• Common causes: Often occurs in tissues containing large or fragile cells such as liver, adult heart, or brain tissue.
• Optimization tip: For necrotic or drug-treated samples, apply Percoll density gradient centrifugation to remove debris and impurities.

Note: When processing large-cell tissues, it is recommended to have the Miltenyi Debris Removal Kit available.

3. High Cell Aggregation (> 20%)

• Primary tissue suspensions commonly show 10 – 20% aggregation. If this range is acceptable for your experiment, further optimization is not necessary.
• If additional reduction is needed, refilter the suspension through a 20–40 μm cell strainer (e.g., Flowmi Cell Strainer, BAH136800040, Sigma-Aldrich), which has been shown to provide effective results.