Sodium Information and Courses from MediaLab, Inc.

The platelet count is only as good as the sample collected. Blood samples that are collected in EDTA or sodium citrate tubes for coagulation purposes should be inverted 5 - 10 times for proper mixing of the anticoagulant and the blood. If the tube is not mixed, small fibrin clots may form, causing a falsely decreased platelet count.

Once released, BNP stimulates natriuresis and diuresis. This action works against aldosterone which conserves sodium and water. BNP causes loss of sodium and water through the kidneys to relieve the ventricular wall stretch. It also increases renal blood flow and glomerular filtration rate.

The composition of CSF has some similarities to plasma. However, most analyte reference ranges are different for CSF than they are for plasma, For example, the protein level of normal CSF is dramatically lower than that of plasma. The following table lists some of the chemicals present in CSF, and their concentrations: Chemical Level sodium 136.0 - 150.0 m Eq/L potassium 2.3 - 2.7 m Eq/L magnesium 2.4 - 3.0 m Eq/L protein 2 - 4 mg/dL (normally diffuses across blood-brain barrier) glucose 45.0 - 60.0 mg/dL calcium 2.1 - 2.7 m Eq/dL cholesterol present in small amounts creatinine 0.5 - 1.2 mg/dL lactic acid dehyrdogenase (LDH) present in small amounts phosphorus (inorganic) 1.0 - 2.0 mg/dL urea 6.0 - 16.0 mg/dL uric acid 0.5 - 3.0 mg/dL

Testing for ketone bodies is based on a nitroprusside reaction. Acetoacetic acid reacts with sodium nitroferricyanide and glycine in an alkaline medium to produce a violet-to-purple colored complex. The urine chemical reagent strip method can detect as little as 5 mg/dL acetoacetic acid in urine. It does not react with acetone unless glycine is present or B-hydroxybutyric acid. Since these two compounds are derived from acetoacetic acid, their presence can be assumed if the test for ketones is positive. Ketones are reported either as negative, small, moderate or large amounts; or negative, 1+, 2+, 3+, or 4+. In some severe cases of ketosis, it may be necessary to perform tests on serial dilutions to provide more information on the quantity of ketones present.

Testing for ketone bodies is based on a nitroprusside reaction. Acetoacetic acid reacts with sodium nitroferricyanide and glycine in an alkaline medium to produce a violet-to-purple colored complex. The reagent strip method can detect as little as 5 mg/dL acetoacetic acid in urine. It does not react with acetone unless glycine is present or B-hydroxybutyric acid. Since these two compounds are derived from acetoacetic acid, their presence can be assumed if the test for ketones is positive. Ketones are reported either as negative, small, moderate or large amounts; or negative, 1+, 2+, 3+, or 4+. In some severe cases of ketosis, it may be necessary to perform tests on serial dilutions to provide more information on the quantity of ketones present.

There are several acids which can be used to precipitate proteins - sulfosalicylic, trichloroacetic, nitric, and acetic acids. Sulfosalicylic acid (SSA) is the most frequently used acid test because it does not require the use of heat. Exton's reagent is 5% sulfosalicylic acid in a solution of sodium sulfate. Exton (1925) found that adding sodium sulfate to the SSA causes a more uniform precipitate to be formed. To perform the SSA procedure mix equal parts of patient urine and the reagent. Rate the amount of turbidity according to the following scale:

The specimen drawn for a mixing study must meet the following conditions for accurate testing: A properly filled 3.2% sodium citrate tube must be collected. Proper centrifugation to create platelet-poor plasma for analysis must occur; the presence of platelet phospholipids can interfere with the mixing study if an anti-phospholipid antibody is present. Testing must be performed within 4 hours of collection.

Denaturing chemicals can be added to the acrylamides during formation of polyacrylamide gels. These additives keep the solutes or molecules in a denatured state during separation. Urea denatures double-stranded DNA to single-stranded DNA. A detergent, sodium dodecyl sulfate (SDS), denatures proteins. Adding SDS with heat denatures proteins to small, similar shaped particles and coats each so that protein structures are not reformed. SDS is usually added to the gel and the protein sample. Then the mixture of protein coated fragments moves through polyacrylamide gel pores with speed similar to a mixture of DNA fragments.

Venous blood specimens for coagulation assays should be collected into a tube containing 3.2% buffered sodium citrate tube (blue top tube), yielding a whole blood sample with a 9:1 blood to anticoagulant ratio. Inadequate filling of the collection tube will decrease this ratio, and may affect test results.A blue top tube used for coagulation testing should be drawn before any other tubes containing additives. This includes tubes containing other anticoagulants and/or plastic serum tubes containing clot activators. A serum tube that does not contain an additive can be collected before the blue top tube.If a winged blood collection set is used in drawing a specimen for coagulation testing, a discard tube should be drawn first. The discard tube must be used to fill the blood collection tubing dead space to assure that the proper anticoagulant/blood ratio is maintained, but the discard tube does not need to be completely filled. The discard tube should be a nonadditive or a coagulation tube.If a blood specimen used for coagulation testing must be collected from an indwelling line that may contain heparin, the line should be flushed with 5 mL of saline, and the first 5 mL of blood, or 6 times the line volume (dead space volume of the catheter), be drawn off and discarded before the coagulation tube is filled.

The Periodic Acid-Schiff (PAS) staining technique is the most widely used procedure for the demonstration of glycogen and certain glycoconjugates. The PAS reaction is a result of aldehyde groups being formed via oxidation using periodic acid. The tissue section is then incubated in a Schiff reagent (a colorless concoction of basic fuchsin, HCl, and sodium metabisulfite). The section is finally rinsed with running water, which causes the fuchsin molecules bound to the glycogen in the tissue to turn pinkish red. Hematoxylin or fast green may be used as counterstains.

The Gordon and Sweet's silver staining method is used to demonstrate reticular fibers. This method relies on the impregnation of retic fibers with silver through oxidation and reduction. The tissue is first oxidized using potassium permanganate to enhance subsequent staining. It is then sensitized using an iron alum solution that targets and binds to the tissue element (retic fibers). The retic fibers are then impregnated by an ammoniacal silver solution that removes and replaces the sensitizer. The silver solution is reduced by 10% formalin so that a visible metallic tone highlights the retic fibers. The metallic silver is then toned and converted to metallic gold using gold chloride solution, by providing better chemical stability, fiber contrast, and clarity. Unreduced silver and excess gold are removed via a 5% hypo (sodium thiosulfate) solution. The tissue section may then be counter stained with nuclear fast red or light green.

Sample type required: Deparaffinized and rehydrated tissue section (3-5 microns) on positively (+) charged slidesPreferred fixative: Zenkers; however 10% neutral buffered formalin (NBF) may be used as wellControl: Skeletal or cardiac muscleReagentTimeTechnical NotesZenker's fixative5 minutes (in heated solution)Used as both a fixative and mordant.Microwave solution for 45 seconds on high power before placing slides inside.Running water wash5 minutesEnsure that ALL traces of the reagent have been removed.Lugol's iodine 5 minutesRunning water wash5 minutesEnsure that ALL traces of the reagent have been removed. 5% hypo solution (sodium thiosulfate)1 to 2 minutesRunning water wash 10 minutes0.25% potassium permanganate5 minutesOxidizesRunning water wash 5 minutes5% oxalic acid Bleach until tissue is colorlessRunning water wash5 minutesDistilled water 3 changesDiscard solution after use.PTAH staining solutionOvernight at room temperaturePost staining procedure: Dehydrate quickly through two changes each of 95% and 100% alcohol, along with two changes of xylene, then cover-slip. Expected results:Cross striations - BlueNuclei - BlueCollagen - Red-brownElastic fibers - Purplish

C. difficile spores resist dessication for months and are known to persist on hard surfaces for up to five months. Spores persist even after exposure to air. Epidemic strain B1/NAP1/027 is known to hyper-sporulate, a virulence-associated characteristic of outbreak strains. Health care workers are important vectors for transmission, as they may carry the spores on their hands or clothing. Alcohol-based hand sanitizers are very effective against non-sporulating organisms but do not kill C. difficile spores or remove the organism from the hands. The CDC recommends thorough hand washing using soap and water for caregivers and family members alike.Patients with C. difficile infection (CDI) should be isolated to a single room with a bathroom or cohorted (roomed) together. Staff treating infected patients should use personal protective equipment (PPE), including at least gowns and gloves, and must wash hands after removing gloves. The use of gowns helps to prevent contamination of clothing. Surfaces should be decontaminated using a solution of 10% sodium hypochlorite (bleach), this is effective in reducing environmental contamination in hospital rooms. The CDC recommends the use of bleach for cleaning patient and staff rooms during outbreaks. Control strategies involving reinforcement of Infection control practices rather than drug restriction are more effective. These practices include:Proper education of staff members involved in care of CDI patientsBetter isolation compliance Use of glovesFrequent and thorough hand washingEnvironmental decontamination

Blood is tested for the most important electrolytes (salts): Sodium (Na) Potassium (K) Chloride (Cl) Carbon dioxide (CO2)Can be run on serum or plasma.

These tubes contain the anticoagulant sodium citrate. They are used mostly for coagulation (clotting) studies. They must be completely filled to assure proper ratio of anticoagulant to blood.They must be inverted immediately after filling to prevent clotting.

Contain either sodium heparin or sodium EDTA anticoagulants, or no anticoagulant. Are used for trace element, toxicology, and nutritional studies.

Blood collection tubes must be filled in a specific order to avoid specimen contamination from the additive in the preceding tube. The following order of draw is an accepted laboratory standard. 1. Tubes or bottles for blood cultures 2. Light-blue top tubes (sodium citrate) 3. Serum tubes (with or without clot activator) 4. Green top tubes (sodium or lithium heparin) 5. Lavender or pink top tubes (Potassium EDTA) 6. Gray (Sodium fluoride and sodium or potassium oxalate)

Semen must be diluted prior to counting sperm if a hemocytometer is used. In additon to preventing overlapping of sperm cells, the diluting fluid immobilizes the sperm in the chamber to further facilitate counting.Following liquefaction (at about 30 minutes), mix the sample manually by swirling the container several times. Thorough mixing is essential for accurate counting. Calibrated automatic pipettes are used to prepare a dilution. Some laboratories may require two separate dilutions, as recommended by WHO 5th edition. Because of the viscosity of semen, the semen should be added to the diluent using a positive pressure pipettor. The dilution often used for routine sperm counts is 1:20 but the actual dilution factor will vary depending on the sperm concentration that was noted during the initial microscopic evaluation. If a high concentration of sperm are noted, a greater dilution will be necessary. For low concentrations, a minimally diluted (e.g., 1:2) specimen may be required. The appropriate dilution is determined by estimating the concentration needed to achieve a count of at least 200 spermatozoa in the area that is counted on each side of the hemocytometer.

A light-blue top tube (a blood collection tube containing 3.2% sodium citrate) that will be used for coagulation testing must be filled to completion. Under-filling the tube changes the ratio of blood to anticoagulant. This can affect the accuracy of coagulation tests that are performed using this specimen. If a winged blood collection device (butterfly) is used to collect a light-blue top tube for coagulation studies, a waste tube should be drawn first, if the coagulation tube is the first tube to be collected for patient testing. The waste tube must also be a light-blue top tube or a tube that contains no additives. This waste tube is drawn first to remove the air in the tubing of the winged collection device. Once blood flows through the tubing, the waste tube can be removed and discarded. The waste tube does not need to be completely filled. If the air is not displaced from the tubing into a waste tube, it will be drawn into the tube used for testing and cause a short-fill of the tube. Less volume of blood in the tube alters the required blood to anticoagulant ratio needed for coagulation studies.

Amorphous urates can be dissolved in dilute sodium hydroxide. Amorphous phosphates will dissolve in dilute acetic acid. In either case, the bacteria will remain.

Alum Hematoxylins: Hematoxylin Oxidizer Mordant Gill's Sodium iodate Aluminum sulfate Delafield's Naturally Ammonium alum Mayer's Sodium iodate Potassium or ammonium alum Harris's Sodium or potassium iodate (mercuric chloride no longer used due to its' toxicity) Potassium alum Ehrlich's Naturally Potassium alum Iron Hematoxylins: Iron salts are used as both the oxidizing agent and the mordant in the following examples: Hematoxylin Oxidizer Mordant Heidenhain's Ferric ammonium sulfate Ferric ammonium sulfate Weigert's Ferric chloride Ferric chloride