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Veterinarian Technician July 2009 (Vol 30, No 7)

Managing the Veterinary Laboratory

by Heidi Moser, BA, RVT

    CETEST This course is approved for 1.0 CE credits

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    Becoming an expert on every aspect of the veterinary clinic is difficult, and taking the time to learn how to properly manage the laboratory in a fast-paced environment may be a low priority. However, learning to maximize the effectiveness of the veterinary laboratory can benefit a practice in many ways. Honed laboratory skills can lead to reliable  patient results and the ability to track disease more accurately.1–4 In addition, a well-managed laboratory has fewer instrument malfunctions, and when equipment problems do arise, troubleshooting is easier. As the focus of veterinary practice has changed over the years, the in-house laboratory has become a reliable profit center.

    In most veterinary reference laboratories, veterinary technicians work with clinical laboratory scientists who are certified to work in human hospitals and diagnostic laboratories. Through education and work experience, medical laboratory technicians (MLTs) and medical technologists (MTs) develop a solid understanding of important aspects of the laboratory, such as quality control and troubleshooting.1,2 Having a veterinary technician with a laboratory background on staff is advantageous because he or she will have gained experience and knowledge from laboratory coworkers. However, because most practices typically do not have such a person on staff, it is important to designate one or two people to oversee the laboratory and be responsible for instrument maintenance and quality control.

    Quality Control

    Every instrument in a clinic must be tested regularly to ensure that it is working properly.1–4 Reference laboratories normally run standards on their analyzers once each shift or after a certain number of samples have been processed. Human hospitals and laboratories run controls with each batch of samples. Control results, along with the technician’s  initials, should be logged into a computer program or tracked on a graph to visually assess trends. This graph should be kept in a common area so all persons using the  laboratory can access it. The results for each quality control session should be checked for accuracy according to the ranges set by the manufacturer before samples from patients are tested. Results are considered accurate when they are close to the mean (average) value of the range.1–4

    If an instrument has multiple levels of quality control, a schedule can be established so that only two of the levels are run each day, thereby reducing costs of supplies and technician time. For example, consider an instrument with three levels of standard quality control. Levels one and two can be assayed on Monday, levels two and three on Tuesday, and levels one and three on Wednesday. This pattern can simply be repeated later in the week. The schedule should be posted near the instrument so everyone has easy access to it.

    Technicians must also evaluate the precision (reproducibility) of quality control results. Precision indicates the similarity between one result and the next.1–4 For example, if one day’s standards are at the high end of the range and the next day’s numbers are at the low end of the range, there may be a problem with the instrument; however, further investigation is necessary to rule out other problems. Although the values are within range on both days, the difference in control values from one day to the next will be reflected in patient results. This could be the difference between normal and abnormal values in the patients that are tested that day.

    Proper handling and storage are important when using quality control material.1,2,4 Many products come ready to use, but some require reconstitution. Reconstitution generally involves mixing a powder with a liquid. Make sure to read the instructions on the package insert. If a certain type of water, such as distilled or deionized water, is required, do not use tap water instead.1,2 Mix gently and frequently, and allow the product to sit for the recommended time before use. For best results, designate certain pipettes or other equipment for this purpose.

    Most products need to be refrigerated and should be allowed to reach room temperature before use; these products should be returned to the refrigerator immediately after use. The person who opens a new bottle should initial and date the bottle. Some products have a limited shelf-life after being opened or reconstituted.

    Instrument Maintenance

    If quality control values begin to drift toward one end of the range, an instrument may need to be calibrated. Calibrators “set” the analyzer to certain points.1,4 In general, controls and calibrators are available for purchase from the instrument’s manufacturer. To avoid instrument drift, periodic calibrations may be necessary. All equipment must be recalibrated when new batches of reagents are purchased. Check the instrument’s user manual for additional suggested calibration intervals, and record dates of calibration in the quality control log.

    Chemistry and hematology analyzers use reagents—substances that induce chemical reactions. Reagents require proper handling and storage.1,4 When a shipment arrives at the clinic, promptly refrigerate reagents that require refrigeration. Also, check the expiration dates when unpacking the shipment. If the expiration date is near and the reagent will likely not be used by that date, ask the supplier for replacement stock with a later expiration date. Some companies will send a replacement at no additional cost.

    All instruments require regular cleaning and preventive maintenance.1,4 After the initial purchase of an analyzer, the manufacturer generally sends a technical representative to train veterinary staff how to use and care for the equipment. The representative should demonstrate all maintenance that the instrument requires. If an instrument is purchased used, the user manual will detail the required maintenance. It is advisable to designate one person in the clinic to perform regular maintenance and keep a maintenance log, which can assist with troubleshooting.

    Like all equipment, microscopes and centrifuges are affected by wear and improper use. Cleaning oil from microscopes after each use results in longer life of the objectives and less cost to the clinic. Periodic cleaning and calibration of centrifuges and replacement of parts as needed also help the veterinary laboratory operate smoothly.1,4


    When quality controls are out of range, many technicians may not know how to proceed. Follow these steps when troubleshooting:

    Step 1. Repeat any control that is out of range. Perhaps improper technique or the wrong bottle of control was used. If the second run is within range, you can generally proceed with running patient samples.

    Step 2. If the repeated result is still out of range, examine the bottle of control to see when it was opened. If it is old or very little liquid is left, open a new bottle. Reconstitute it, if needed, and allow it to sit as recommended. This can be a time-consuming process, but if it is rushed, the control may not mix properly and may be rendered useless, costing the clinic even more time and money.

    Step 3. If the new, properly handled quality control does not work, instrument maintenance or calibration may need to be performed. Check the logs to see when they were last performed.

    Step 4. Along with checking maintenance and calibration logs, examine the reagent(s) to see how long it has been in use and if it has expired. Replace good reagent only after repeating the controls and calibrating the instrument to try to correct the problem.

    Step 5. If all of the above steps have been taken, it is necessary to call technical support. Instrument service may need to be scheduled.

    In many cases, a service contract is included with the purchase of an instrument; in other cases, such as when used equipment is purchased, it is advisable to purchase a service package, as some companies charge a large fee for a service call.

    Working with the Reference Laboratory

    Many practices have an in-house laboratory and use outside testing as well. This can be very cost effective for a practice. Some tests are not ordered very often, so buying a new instrument or keeping a little-used reagent on hand can be costly.3,4 Purchasing an instrument may be advisable if a practice begins ordering a certain test often. Eventually, the savings make up for the initial cost, but purchasing equipment for some results, such as electrolyte or digoxin levels, will not be cost effective. These tests can be sent to a reference laboratory.

    When you send samples to a reference laboratory, your samples join many similar shipments from other clinics. It is important for technicians to clearly label all samples with the animal's complete name, regardless of whether the sample is sent to a reference laboratory or is analyzed in house.1 Good quality control and state-of-the-art equipment are useless if canine blood drawn for a routine complete blood count becomes confused with feline blood meant for FIV testing.

    Make certain to include the requisition with the sample and thoroughly and accurately prepare the paperwork to avoid delays in testing. It is often helpful to include other relevant information about the patient's case. For example, if the veterinarian suspects Babesia infection, note it on the requisition.

    Quality Assurance

    Some people confuse quality control with quality assurance; the two are related but different. Quality control is specific to a particular instrument in the laboratory, whereas quality assurance denotes an all-encompassing approach to the laboratory.1

    Factories often have quality assurance departments or personnel who systematically examine the product and the methods of production. In the veterinary clinic, particularly in the laboratory, there also are ways to verify results and methods. One way is to ensure that employees are trained correctly and consistently.1 Creating standard operating procedures (SOPs), which are periodically evaluated and updated, is a good place to start. Check-off sheets can serve this purpose as well. Once all employees are properly trained, "blind" samples can be given to each technician to be evaluated. Chemistry and hematology samples with known results can be distributed to determine whether each employee uses proper technique. Previously evaluated blood smears and urine specimens can also be used as blind samples to ensure that results are consistent from one technician to another.

    Continuing education for staff is required. Technicians can be assigned topics to research and present as time allows. If a staff member reports unusual findings on a blood smear, urinalysis, or fecal flotation, encourage him or her to set aside the sample so that everyone may examine it and learn. Urine and fecal wet preps can be set inside a Petri dish with moistened gauze to keep them readable.


    Safety in the veterinary clinic is commonly viewed as avoiding cat scratches and dog bites, but body fluids and chemicals can also be hazardous. While animals do not transmit notorious infectious agents such as HIV or hepatitis C, they may transmit several zoonotic diseases. In addition, some quality control products are derived from human serum. Therefore, personal protective equipment (PPE)1,2 should be worn when working with body fluids or handling standards.

    Reagents and cleaners can be caustic to skin and eyes. If there is potential for splashing, safety glasses should be worn in addition to gloves — particularly if you are working with any basic solutions. For instance, bleach can be dangerous if it enters the eyes. The clinic must have a material safety data sheet (MSDS) book that describes every chemical used in the laboratory and any potential dangers.1

    1. Turgeon ML. Clinical Laboratory Science: The Basics and Routine Techniques, ed 4. St. Louis: Mosby; 1999.

    2. Walters NJ, Estridge BH, Reynolds AP. Basic Medical Laboratory Techniques, ed 4. Albany, NY: Delmar Publishers; 2000.

    3. Duncan JR, Prasse KW, Mahaffey EA. Veterinary Laboratory Medicine: Clinical Pathology, ed 4. Ames: Iowa State University Press; 2003.

    4. Hendrix CM, Sirois M. Laboratory Procedures for Veterinary Technicians, ed 5. St. Louis: Mosby; 2007.

    References »

    NEXT: NAVTA Announces New Veterinary Technician Specialties

    CETEST This course is approved for 1.0 CE credits

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