Final answer:
Arterial blood samples are kept on ice to slow down metabolic processes like glycolysis, which continue post-draw and can alter test results. Chilling the samples also preserves unstable components like RNA by inhibiting enzymatic degradation. Ultra-low temperatures are used for long-term storage or transport to prevent sample deterioration.
Step-by-step explanation:
Arterial blood samples should be kept on ice after collection to prevent metabolic processes, such as glycolysis, which can continue even after the blood has been drawn. Glycolysis can lead to a decrease in glucose levels and an increase in lactate concentrations, potentially altering the results of various blood tests and making them inaccurate. Keeping the samples on ice slows down these biochemical reactions significantly. Additionally, some blood components, like RNA, are quite unstable and can be rapidly degraded by enzymes at room temperature, so chilling samples is essential to preserve their integrity.
For instance, when collecting blood samples into tubes containing anticoagulants such as K2EDTA or lithium heparin, samples are often centrifuged to obtain plasma which must then be managed carefully. According to best practices, plasma samples should be quenched with methanol and analyzed immediately or kept chilled to ensure accurate results.
In a broader context, various biological samples, whether bacterial cultures or medical specimens like blood or urine, may require specific temperatures for long-term storage or transport to prevent deterioration. Utilizing ultra-low temperatures for storage is a standard approach to preserve these samples.