Microwave Information and Courses from MediaLab, Inc.

Procedural Step Comment Caution Greet and positively identify patient Always use at least two patient identifiers to ensure positive patient identification. Never rely on name placards that are placed on or near the patient's bed or crib to identify the patient. If there is a discrepancy in identification, do not proceed until the discrepancy is resolved. Explain the procedure If the patient is a small child, be at eye level when explaining the procedure. Also explain the procedure to the parent(s). If the patient is aware of what will be happening there is less chance of the patient suddenly jerking away his/her hand when the puncture occurs. Position patient appropriately An outpatient who is a small child should sit on the parent's lap. If necessary, seek assistance for finger puncture if the patient is a small child. Cleanse hands and put on gloves Use soap and water or alcohol-based gel to cleanse hands. Cleanse hands before donning gloves and after removing gloves. Warm puncture site if needed Use the method that is approved by the laboratory for prewarming the puncture site. Never use a moist cloth that has been heated in a microwave as this may cause injury to the patient. Gather appropriate equipment Only have needed equipment at hand. Keep track of ALL equipment to prevent patient injury. Cleanse the puncture site Use 70% isopropanol unless the patient is sensitive to alcohol. Allow the site to air dry. Performing the puncture before the alcohol has dried may hemolyze the blood specimen. Securely grasp and puncture finger Puncture the side edge of the fleshy pad of fingertip. Avoid extreme side and tip of finger. Discard puncture device into appropriate container Puncture device should be discarded into a sharps container that is puncture-proof, has rigid sides, and has a lid Do not discard puncture devices into regular trash or biohazard bags. Injury to personnel who handle these bags may occur. Wipe away the first drop of blood Use slight pressure to facilitate blood flow. The first drop of blood contains tissure fluid that may contaminate or dilute the blood specimen and affect test results. Collect blood into container Allow blood to flow freely into the collection device. Tap the container gently on a hard surface to move blood further down into the tube if necessary. Do not "milk" the finger or scrape the collection device across the finger to obtain specimen; both actions may cause the specimen to hemolyze. Mix specimen immediately upon completion of the collection. Apply pressure to the puncture site to stop the bleeding. Use gauze to apply pressure to the puncture site. It is not advisable to apply an adhesive bandage over the skin puncture site if the child is less than two years old as the child may place the bandage in his/her mouth. Label specimen Specimen must be labeled in the presence of the patient. Unlabeled specimens will be rejected by the laboratory.

In addition to the puncture device, additional equipment may be required when performing a successful dermal puncture.Plastic microcollection devices: Plastic microcollection devices are small plastic tubes designed to collect capillary blood from a dermal puncture wound. Each small collection tube is color-coded in the same manner as blood collection tubes used for venipuncture. The color of the cap of each container tube corresponds to the type of additive inside the tube, most often an anticoagulant. The additive coats the inside of the tube. Examples of microcollection devices are shown below. Heel warmer: It is best practice to warm the heel of an infant with a warming device known as a heel warmer. The heel warmer, when activated, is designed to warm its contents to a standardized temperature. This temperature will be hot enough to effectively warm the heel and facilitate blood flow to the area without causing heat injury to the patient. It is unacceptable to warm a cloth using a microwave. There may be "hot spots" on the cloth that could potentially burn the patient. Keep in mind, what may feel warm to you, the phlebotomist, may feel hot to your patient!Plastic or Mylar-wrapped capillary tube: In some facilities blood from a capillary puncture is collected directly into a capillary tube. These tubes are very delicate and must be used with great caution. As soon as the tube is two thirds to three-fourths filled, one end is sealed to prevent blood from leaking out.Glass microscope slides: In some facilities, the person collecting the capillary specimen may also be required to prepare a blood smear for laboratory examination. A drop of blood is placed directly on a glass slide and spread to create an area for cell examination. If you are required to prepare blood smears, remember that the slide is considered infectious until fixed or stained. It is also important to remember that glass is a sharps hazard. If not used correctly, the glass may cause injury to both the patient and the phlebotomist. Be as cautious with a glass slide containing blood as you are with a contaminated needle. Dispose of glass slides that will not be used for testing in approved sharps containers.Alcohol and gauze pads: Alcohol is the disinfectant of choice for dermal puncture. The alcohol must be allowed to air dry, which will prevent hemolysis of the specimen and discomfort for the patient. A piece of clean or sterile gauze is used to wipe away the first drop of blood. Gauze is also used to apply pressure to the wound after the specimen collection is complete to stop the wound from bleeding.Iodine or other approved cleaning agents may be used as an alternative to alcohol.Bandage: It may be necessary to apply a bandage to the puncture wound on a finger or heel if the site continues to bleed. However, it is NOT recommended to bandage the finger of a child who is 2-years-old or younger since the bandage may become a choking hazard if the child puts that finger in his/her mouth.Personal protective equipment (PPE): All healthcare professionals that may come in contact with blood and/or body fluids while performing a laboratory procedure are required to wear intact gloves. It is against safety guidelines to alter gloves in any way that may compromise the integrity of the gloves. Eye protection, such as safety goggles, is recommended if there is the possibility of a splash of blood while collecting a capillary blood specimen. In many facilities, special gowns are required in some patient areas such as special-care nurseries. Always follow the policies of your facility in regard to PPE.

Microwave ovens are commonly used in the histopathology laboratory to help expedite special staining procedures and improve diagnostic turnaround times. Staining solutions (with or without slides) are often heated in the microwave to increase the rate at which the dye or other reagent is diffused throughout the tissue sample.

While microwave use in the laboratory is considered to be relatively safe, the following safety precautions should be taken to prevent high doses of exposure to microwaves and personal injury: Periodically inspect and clean door seals and hinges. Use a microwave leakage detector to check for microwave leakage from the door seals on a regular basis. Always handle containers with potholders or thermal mitts. Never operate the microwave without a minimum volume of microwave-absorbing material inside the container. Never heat food in a microwave oven used for laboratory procedures.

While microwave use in the laboratory is considered to be relatively safe, the following safety precautions should be taken to prevent high doses of exposure to microwaves and personal injury:Periodically inspect and clean door seals and hinges.Use a microwave leakage detector to check for microwave leakage from the door seals on a regular basis.Always handle containers with potholders or thermal mitts.Never operate the microwave without a minimum volume of microwave-absorbing material inside the container.Never heat food in a microwave oven used for laboratory procedures.

Sample type required: Deparaffinized and rehydrated tissue section (3-5 microns) on positively (+) charged slidesPreferred fixative: 10% neutral buffered formalin (NBF)Control: Internal; appendix, fallopian tube, uterus, or small intestine are recommended choicesReagentTimeTechnical NotesBouin's solution15 minutes (in heated solution)Used as both a fixative and mordant.Microwave solution for 1 minute before placing slides inside.Running water wash5 minutesEnsure that ALL picric acid (yellow) has been rinsed clear.Weigert's working hematoxylin10 minutesRunning water wash5 minutesRequired for nuclear bluing.Distilled water3 changesBiebrich scarlet acid fuchsin5 minutesDistilled water3 changesPhosphotungstic/phosphomolybdic acid10 minutesDiscard solution after use.Aniline blue5 minutesDistilled water3 changes< 1% acetic acid1 minuteDiscard solution after use.Post staining procedure: Tissue section should be dehydrated with 95% and absolute alcohols followed by two changes of xylene and then coverslip. Expected results:Nuclei - BlackCytoplasm, muscle, erythrocytes - RedCollagen - Blue

Bancroft JD, Gamble M, eds. Theory and Practice of Histological Techniques. 6th ed. Philadelphia, PA: Churchill Livingstone Elsevier; 2008.Carson FL, Hladik C. Histotechnology, A Self-Instructional Text. 3rd ed. Chicago, IL: ACSP Press; 2009. Kumar GL, Kiernan JA, eds. Special Stains and H & E. 2nd ed. Carpinteria, CA: Dako North America; 2010. Available at: http://www.dako.com/08066_guide_to_special_stains.pdf. Accessed April 24, 2012.Moore J. Special Stains Using the Microwave. EBSciences web site. Available at: http://www.ebsciences.com/papers/moore.htm. Accessed April 24, 2012.The Biological Stain Commission website. Available at: http://www.biologicalstaincommission.org/. Accessed April 24, 2012.