Chemistry Information and Courses from MediaLab, Inc.

Each specimen tube is used for a different purpose:first tube - chemistry/serologysecond tube - microbiologythird tube - hematologyfourth tube - cytology/miscellaneous

External quality control is performed to ensure the reliability of test results between different laboratories. It is also required by CLIA for laboratory accreditation. External quality control is generally accomplished through proficiency testing (PT). In proficiency testing, simulated patient samples are sent out to laboratories for testing. The CLIA standards for handling proficiency testing specimens are as follows: PT samples must be tested with the laboratory's regular patient load. PT samples must be tested the same number of times that patients' samples are tested routinely. Laboratories participating in PT programs must not engage in interlaboratory comparison of PT sample results. Laboratories may not send PT samples to another laboratory for analysis. Laboratories must document all steps of processing for PT samples. PT is required for only the primary method used for testing of analytes in patients' samples during the period covered by the PT event.In return for their participation, the laboratory will receive the following information: results for each analyte sample mean result for each analyte standard deviation of results by the comparative method number of laboratories using the same method standard deviation index (SDI) lower and upper limits of acceptability of resultsPT results that are between the lower and upper limits of acceptability are considered satisfactory. For chemistry, 80% of samples must test within the acceptable range for the PT to be considered successful. External quality control serves several purposes, including: providing a check on internal quality control detecting errors in a lab's methods providing a comparison of testing methods, which is useful in selecting new methods

Public health laboratory scientists are also regulated by the Board. The table below outlines the various requirements for applicants to receive licensure for a public health laboratory. Public Health Laboratory RequirementsDirectorFulfill the same requirements as a clinical laboratory directorSupervisorBe certified by National Registry in Clinical Chemistry or American Society for MicrobiologyBe licensed as a technologistHave five year's relevant experiencePass the state examTechnician (microbiology)Have a Bachelor's degree in one of the biological sciencesObtain American Society for Microbiology or the National Registry in Microbiology Certification in Public Health Microbiology Technician (chemistry)Have a Bachelor's degree in one of the chemical, biological, or physical sciencesObtain National Registry of Clinical Chemistry Certification in Public Health ChemistryTechnician (conditional)Have a Bachelor's degree in one of the chemical or biological sciencesPerform tests only under the direct supervision of a licensed pathologist, director, supervisor, or technologist.Receives a conditional two-year license, which may be renewed only once A license from the Board of Clinical Laboratory Personnel allows you to work in a public health laboratory at the same level and specialty.

Specialists in immunohematology perform all testing prior to blood transfusions and work to prevent transfusion infections. They also investigate any post-transfusion reactions. This specialty includes all lab procedures performed in the specialty of histocompatibility. Specialists in clinical chemistry analyze body fluids such as blood, urine, and spinal fluid to determine the chemical makeup, including the amount of carbohydrates, proteins, enzymes, and trace elements. The special covers urine microscopics and chemical evaluation of the liver, kidneys, lungs, heart, and other vital organ systems. This specialty also covers all testing performed in the specialties of radioassay and blood gas analysis. Specialists in blood banking can perform all immunohematology testing as well as testing from the specialties of clinical chemistry, hematology and serology/immunology that relates to donor blood. Specialists in immunohematology, clinical chemistry, hematology, and serology / immunology may perform all tests in the blood banking specialty.

The setting is automated chemistry department, night shift, busy core laboratory for a hospital based outreach laboratory. A medical technologist who operates the automated chemistry analyzer on third shift encounters short samples a couple of times a night. When this happens, he runs as many of the ordered tests as he can and fills in the blank results with a comment indicating that a short sample occurred. As far as he knows there isn't a policy that addresses this problem directly.The test reports out with the results and the comments. The technologist does not have to change the physician order in any way and is providing the maximum results that can be reported for the specimen in a timely fashion. This is done as a matter of patient care and quality service. There has not ever been a complaint about this practice as far as he knows. Are there any additional steps this technologist should be taking?Correct Answer: The technologist should follow the procedures that the laboratory has in place for testing and billing samples for which there is no order or for ambiguous orders. If the policies do not seem to address his particular situation, he thinks there should be a separate policy to cover this situation or has a question about it, he should talk to his supervisor or to the laboratory compliance officerDiscussion: This choice addresses the problem in the most complete manner, in that the employee fulfills his responsibility to take action when he thinks there is a problem.

Therapeutic Drug Monitoring (TDM) is a branch of clinical chemistry that specializes in the measurement of medication levels in serum. TDM requires quantitative measurements of drugs and/or their metabolites.

Marcie Moore was a phlebotomist at a community hospital in Atlanta. It was her week to collect the pediatric unit and she was on her way to the room of a newborn for which she had just received orders to draw a STAT BMP (chem-7) and bilirubin. After informing the mother of the baby about the test she needed to perform, Marcie set up to perform a heel stick on the baby. Marcie chose a site on the outer edge of the heel on the bottom of the baby’s foot ( the correct area for a heel stick) and made a small incision with a Tenderfoot lancet after cleaning the site well with alcohol.She immediately began collecting the blood in the correct tube for the BMP and bilirubin. Blood flow was not strong so Marcie squeezed the baby’s foot a little to help the blood come out faster – the newborn was screaming and Marcie could tell it was making the mother uncomfortable. She wanted to hurry and get done so the mother could hold the baby.After the chemistry tech ran the blood tests on the tube, she informed Marcie that the newborn had a panic potassium level which did not coincide with the previous blood work on the newborn. Also the chemistry instrument could not perform the bilirubin due to hemolysis. Marcie was asked to recollect the specimen.

Validated material for the different testing areas in a laboratory (such as chemistry, hematology, and microbiology) are provided several times a year. Participating laboratories test the specimens and return results to the proficiency testing source. The laboratory’s performance is then evaluated using the comparative method mean as the target value plus or minus a defined limit. In general, the evaluation report will show: number of laboratories comprising the peer groupcomparative mean of the group for that particular analyte the laboratory’s performance compared to the peer group whether the performance was satisfactory or unsatisfactory.