Chapter 16

• Tubes with additives should be inverted gently and completely 5-to-10 times immediately after being drawn.
• Thorough mixing allows the additives to be evenly-distributed-throughout-the-sample
• Gentle inversion minimizes hemolysis.
• An efficient and safe way to transport samples is in a leak-resistant-bag-with-zip-closure.
• Specimens transported from outside a hospital laboratory are

  carried in crush-resistant-containers-with-absorbent-material inside and biohazard labels outside the container.
• Ongoing glycolysis (metabolic sugar breakdown within cells)

  within the specimen is a primary cause of inaccurate test results.
• the longer the interval, the more likely the results will be inaccurate.
• The quality of test results depends heavily on the time between when-the-sample-is-drawn-and-when-it-is-analyzed.
• As a general rule, an uncentrifuged blood sample should be delivered to the laboratory within 45 minutes of being drawn
• According to the (CLSI), no more than 2 hours should pass between collection and separation by centrifugation of cells from plasma or serum.
• The appropriate storage temperature depends on the sample-type-and-tests-ordered.
• A few sample types can wait longer before processing without loss-of-viability.
• Whole blood specimens collected in EDTA for CBCs are stable for 24 hours.
• blood smears made from such samples must be done within 1 hour of collection.
• blood smears made from such samples must be done within 1 hour of collection because EDTA-will-eventually-distort-cell-morphology.
• Temperature extremes can cause hemolysis.
• Samples that do not require cooling or warming should be kept at room temperature during transport.
• Specimens that must be maintained at 37° C during transport and handling include cold-agglutinins-cryoglobulins-cryofibrinogen.
• The tubes for these WARM specimens should be warmed using a heel-warmer-packet
• Heel warmers are effective up to 30 minutes.
• Some tests require warming of the sample in a 37° C heat-block before testing
• Patients with certain types of blood-disorders may have acquired cold agglutinins, which can cause problems with testing by automated instruments.
• To prevent this, the EDTA tube for a CBC must be prewarmed-and-kept-warm.
• Chilling a specimen slows metabolic processes and keeps analytes stable during transport and handling.
• A blood-gas-sample needs to be chilled if its delivery to the lab will be delayed.
• To chill a sample, place it in a slurry-of-chipped.
• Avoid large ice cubes, as these may cause part of the sample to freeze.
• If the specimen is being delivered outside the facility by courier, it may be placed in an insulated container to protect it from extreme heat or cold.
• Bilirubin is the most common light-sensitive analyte;
• To prevent light exposure, samples are collected in amber-colored-microtubes.
• or an amber/brown-biohazard-bag, and placed inside a brown envelope or heavy paper bag.
• How a sample is transported to the laboratory depends on the size-of-the-institution-and-the-degree-of-specialization-within-it.
• Some institutions use a pneumatic tube system, in which samples are carried in sealed plastic carriers that travel within a network of tubes.
• Shock-absorbing foam inserts are placed in carriers to reduce the shaking and agitation of the sample during transport
• Samples are first routed to a central station and then sent on to the lab.
• Pneumatic systems are often used for the delivery of paperwork and

  other items but are not always appropriate for blood samples.
• Some larger laboratories may have self-contained-motorized-carriers that run on a track between departments within the laboratory for transporting specimens.
• Special containers are used to protect the sample and prevent contamination of other material during transport
• The OSHA requires PPE to be worn during sample processing.
• Specimens entering the lab are usually first handled by central processing.