Answering your questions on a microscopic exam with negative urine dipstick, RIA lab staffing, MT retraining programs, and phlebotomy trays

Feb. 1, 2002
Edited by Daniel M. Baer, MDNegative urine dipstickQ: If the urine is normal color and clear, and the urine dipstick tests (other than glucose elevation) are negative, is a microscopic exam necessary? Diabetics frequently demonstrate yeast infections. Would these be missed, or can we rely on the leukocyte esterase to be positive in a yeast infection because of increased
A: The key to this question is that the urine is of normal color and clear. It is true that diabetics frequently demonstrate yeast infections. However, if yeast (and white blood cells) were present, they would be seen as a lack of clarity in the gross urine specimen. Microscopic examination of the urine sediment should be performed when the color is abnormal, the specimen is not clear, and any reagent strip tests (except glucose or
urobilinogen) are positive. If glucose were the only positive finding, the urine clarity should be observed with special care, so as not to miss a yeast infection. The presence of white cells might result in a positive leukocyte esterase test; however, the test is fairly insensitive. According to the reagent strip manufacturers, the leukocyte esterase test requires 5 to 15
wbc/hpf (Multistix, Bayer Corp. Diagnostics Division, Tarrytown, NY) or 10 to 25 cells/L
(Chemstrip, Roche Diagnostics Corporation, Indianapolis, IN) to show a positive reaction. Yeast itself does not result in a positive test for leukocyte esterase. Therefore, a urine specimen might show a lack of clarity, from the presence of yeasts and white cells, before the LE test is positive. 
Karen M. Ringsrud

Assistant Professor
Department of Laboratory 
Medicine and Pathology
University of Minnesota Medical School
Minneapolis, MN
RIA staffingQ: I currently supervise a radioimmunoassay
(RIA) lab within a nuclear medicine department. Our management asked for accepted standards for testing times and test/personnel (FTE) ratios for lab tests in general. Is there an accepted standard for this in the blood testing industry? Apparently such standards exist for imaging (radiology) procedures.
A: Although there are staffing guidelines for nuclear imaging and radiology procedures, I am not aware of any for RIA testing. I inquired at the Department of Veterans Affairs, the nations largest healthcare provider. They have none. Even if such standards existed, they would be difficult to interpret and use. This is because most of the straightforward analyses that had formerly been done by RIA have been replaced by automated immunochemical assays, leaving only the complex RIA procedures. Staffing guidelines are difficult to apply to complex procedures. They work best with high-volume, frequently performed tests.Daniel M. Baer, M.D.
Professor Emeritus
Department of Pathology
Oregon Health Sciences University 
Portland, OR
MT retraining programsQ: I am an old
MT(ASCP) who has been out of the field for 20 years. Id like to get back into the field now that my kids are older. Any helpful info you could suggest on the best way to do that? Are there any refresher programs for people like me? 
A: The tight labor market and reduction in the number of schools of medical technology has made this a good time for inactive medical technologists to sharpen their skills and reenter the profession. There are several ways a rusty technologist might consider getting refresher training: a formal refresher program at an educational institution; workshops given by a hospital or professional society; a self-study program from an educational institution or an association; and internship in a lab.I asked a number of educators about refresher training, but got only negative answers. We were unable to find any organization or educational institution that provided this kind of education. Check with your areas school of medical technology. There is an Internet link to many of these,
Many national and state medical technology professional societies have periodic meetings at which there are workshops covering a wide range of laboratory topics. You can find out what is available in your area by searching the Internet. Start with the ASCLS website It has links to the state association sites.
A number of educational organizations were founded to provide continuing education to medical technologists in remote areas, who were dependent on the education coming to them.
CACMLE,, is one such organization. It has self-study programs that are oriented toward the technologist who wants refresher training.
Some pathology departments have Internet sites with extensive information. One of the best is the University of Iowa. The medical school there has developed the virtual hospital website
( that has an extensive Physicians Office Laboratory
(POL) course covering both technical and administrative aspects of operating a
POL. Among the chapters are training modules in microbiology, hematology, and urinalysis. There is no charge for the course, but there is a charge for continuing education credit. The University of Michigans Internet Resources for Pathology and Laboratory Medicine website
( provides links to many other laboratory medicine sites. The University of Washington, Laboratory Medicine Department site
( advertises a series of tutorial CDs that could form the basis of a refresher program. These CDs are expensive and intended to be used by labs or schools rather than individuals. If a local lab or school owns them, it might be possible to arrange to use them as part of your self-study program.
Finally, if there is a shortage of qualified medical technologists in your area, you might be able to arrange to get training at a local lab. Daniel M. Baer, M.D.
Professor Emeritus
Department of Pathology
Oregon Health Sciences University 
Portland, OR
Phlebotomy traysQ: Are there any rules relating to placing phlebotomy trays on the patients bed, bedside table, or other room furniture while drawing blood?A: This issue is not addressed directly in NCCLS
standards. However, from an infection control standpoint, it is easy to see how phlebotomy trays could carry bacteria from room to room or patient to patient. In keeping with sound infection control procedures, therefore, it is not advisable to bring phlebotomy trays in contact with surfaces to which patients would likely be exposed. These include the patients bed or other furniture, bedside trays, or night stands. A periodic cleaning of the surfaces of the phlebotomy tray with a solution of 10 percent bleach further protects patients from nosocomial infections. 
Dennis Ernst,

The Center for Phlebotomy Education
Ramsey, IN 
ReferenceGarza D. Becan, McBride K. Phlebotomy Handbook. Fifth Edition. Stamford, CT: Appleton & Lange; 1999.Daniel M. Baer is professor emeritus of laboratory medicine at Oregon Health Sciences University in Portland, OR, and a member of MLOs editorial advisory board.©
2002 Nelson Publishing, Inc. All rights reserved.