Samples of human tissue, blood and serum are the basic materials used to advance clinical and basic research into a host of significant human diseases. In order to preserve tissues and cells collected for scientific purposes, a number of important techniques and protocols must be utilized. Moreover, the predominant methods in widespread use, cryopreservation and hypothermic storage, have shortcomings in application and assessment. Due to problems with dated information, protocols for the preservation of cells provide suboptimal results, lack detail and do not take advantage of modern day preservation media. Diseased tissue specimens taken from human tissue samples depend on adherence to strict procedures in order to be used successfully. We explore some of the details and best practices of how cells and tissues can be effectively preserved for scientific inquiry.
Cryopreservation of cells is a simple process but there are some subtleties that it is best to be aware of in order to utilize the process successfully. The major factors are an understanding of the cryopreservation media, temperature, freezing profiles and viability assessment. These factors are all important but an emphasis is placed on the media which studies have shown is the most significant component. Using specially formulated cell preservation media at low temperatures is the recommended method. Cells should be added to cold solution as warm solution can significantly damage cells. Additionally, assessment of sample yield and viability should be carried out after monitoring the sample for at least 24 hours post-thaw.
Cells and tissues may be stored using refrigeration for short periods up to a number of days. Hypothermic or cold storage uses special media to prevent cold shock damage to the human tissue samples and cells collected. The life of living samples can be extended via these methods as well providing for extended investigation time.
Successful use of human tissue samples and preserved cells depends on accurate sample assessment. Membrane-integrity assays used immediately after thawing often provide inaccurate results because of delayed-onset cell death due to preservation. Samples compared 24 hours post-thaw with metabolic or biochemical assays yield more accurate assessments.
Cryopreservation and hypothermic storage provide for human tissue and cell specimens to be successfully preserved and stored for research purposes. Frozen tissue samples are crucial to the progress of scientific inquiry into the identification and progression of many important diseases. An understanding of how best to implement the necessary protocols is crucial to protecting the human tissue samples taken from donors.