Tissue Sample Preparation Recommendations

Fresh Frozen Tissue Samples

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Fresh Frozen Tissue Samples

It is recommended to work in an RNase free environment to avoid degradation of RNA molecules. Always use fresh RNAse free reagents for sample preparation.

Samples Preparation Recommendations

Fresh Frozen tissue samples embedded in OCT with no pre-fixation are recommended for optimal results.

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  1. Dissect the tissue in RNAse free conditions and perform immediate freezing.
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  1. Freeze samples directly on dry ice or in isopentane.
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  1. Place tissue samples in OCT (Optimal Cutting Temperature) compound. Store at -80°C (or similar) for up to 6 months for optimal RNA preservation.
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  1. When possible, we recommend to cut fresh frozen tissue for optimal performance of ISS. Section tissue according to best practice and immediately keep on dry ice or at 80°C (or similar). Cut section at a thickness of 10 µm +/- 5 µm on SuperFrost® microscope slides (ThermoFisher Scientific). You can place several sections (corresponding to the approximate size of the SecureSeal chamber format you will use) on one slide with few mm distance between them. Avoid folds as it results in strong autofluorescent background and influences the outcome of the ISS.
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  1. You can store sections at -80°C (or similar) for up to 4 weeks.

If possible, check the RNA quality by Bioanalyzer before using the samples for HS Library Preparation. We recommend a RIN value > 7 for ISS.
Note: Lower RIN values indicate sub-optimal RNA integrity which will impact the performance of the ISS assay.

Please contact us (at support@cartana.se) if you are interested in sequencing samples with RIN value below 7.