CC Lec Mod 1

• The scope of clinical chemistry includes:

  • Instrumentation
  • Quality management
  • Laboratory safety
  • Specimen collection and processing
  • Analytes
• Clinical chemistry is a quantitative science concerned with measuring biologically important substances (analytes) in body fluids
• Clinical blood chemistry analysis covers the analysis of blood chemical components like carbohydrates, lipids, non-protein nitrogen, blood electrolytes, hormones, proteins, enzymes, and blood gases
• Clinical chemistry links general chemistry, organic chemistry, and biochemistry with an understanding of human physiology
• The primary purpose of a clinical chemistry laboratory is to perform analytic procedures that yield accurate and precise information, aiding in patient diagnosis and treatment
• History of Clinical Chemistry:

  • Body chemistry analysis has a long history, with early emphasis on body fluid analysis
  • Observations were made on urine and feces due to ease of collection
  • Analytical methods have evolved from qualitative to quantitative over time
  • Results obtained today using sophisticated methods compare well with those from over 100 years ago
• In ancient times, physicians used crude methods of analysis, such as observing urine specimens and listening to internal body sounds for diagnoses
• Hippocrates in ancient Greece attributed disease to abnormalities in body fluids and made connections between blood and pus in urine to disease presence
• In the 1600s, the microscope was invented, allowing scientists to study structures like plant cells
• Advances in the study of diseases like diabetes were made in the late 1700s, including tests for sugar in urine using yeasts
• By 1918, hospitals were required to have adequately equipped laboratories, and by the 1920s, many US hospitals had laboratories
• In the 1930s, methods were developed for clinical determinations of various enzymes and proteins in blood and urine
• The 1940s brought developments like photoelectric colorimeters and vacuum collection tubes for blood
• In the 1950s, methods for measuring enzymes and quality control charts were introduced in clinical laboratories
• The 1960s saw rapid technological development in clinical chemistry, including the introduction of the AutoAnalyzer and flame photometry
• New technologies and methods continue to be introduced in clinical chemistry, with analyzers evolving from large to smaller, more portable devices
• The clinical chemistry laboratory provides accurate measurements of biochemical markers for patient management
• Biochemical investigations are used for diagnosis, prognosis, monitoring, and screening in various diseases
• Quantitative analysis in clinical chemistry involves measuring analytes dissolved in body fluids, providing valuable information for diagnosis and treatment
• Blood chemistry tests can be routine or special, with routine tests reflecting general health conditions and special tests ordered for specific diagnoses or monitoring
• Medical laboratory scientists in the clinical chemistry section play vital roles in providing accurate and precise biochemical test results for patient care
• Roles of medical laboratory scientists in the clinical chemistry section include:

  • Calculating basic laboratory mathematical problems
  • Practicing quality assurance and laboratory safety
  • Performing correct specimen collection and processing
  • Applying concepts and principles of instrumentation
  • Adapting policies and procedures in clinical chemistry analysis
  • Recognizing and solving common problems in the laboratory
  • Demonstrating punctuality and professional behavior
  • Conveying knowledge on biochemical substances interactions
  • Being responsive to new perspectives and feedback
• In single-celled organisms, substances can easily enter the cell due to a short distance, while in multicellular organisms, the distance is larger because of a higher surface area to volume ratio
• Multicellular organisms require specialised exchange surfaces for efficient gas exchange of carbon dioxide and oxygen due to their higher surface area to volume ratio
• Borosilicate glass has silica and boron trioxide as the main glass-forming constituents
• Borosilicate glass has low thermal expansion, making it able to withstand higher temperature gradients and sudden temperature changes
• Borosilicate glass is highly resistant to water, neutral and acid solutions, concentrated acids, and their mixtures, as well as to chlorine, bromine, iodine, and organic matters
• Borosilicate glass is known commercially as Pyrex or Kimax
• Alumina-silicate glass has greater chemical durability and can withstand higher operating temperatures than borosilicate glass
• Alumina-silicate glass is particularly suitable for use as a gauge glass and is used for high-precision analytical work
• Vycor glassware can be used at much higher temperatures than borosilicate glass, up to 1200°C intermittently
• Soda-lime glass is known for its excellent chemical and physical properties and is used to make pipettes
• Low actinic glassware is tinted dark brown or amber to protect light-sensitive chemical compounds from radiation
• Disposable glassware is made to be used and discarded without the need for cleaning
• Plasticware is replacing glassware in laboratories due to its high resistance to corrosion and breakage, as well as varying flexibility
• Plasticware is less expensive and more durable than glassware, unbreakable, and preferred for certain analyses where glass can be damaged by chemicals
• Types of plastic include Polystyrene, Polyethylene, Polypropylene, Tygon, Teflon, Polycarbonate, and Polyvinyl Chloride
• Plastics used in laboratories include containers, carboys, plastic test tube racks, graduated cylinders, and centrifuge tubes
• Polyvinylchloride (PVC) is used for tubing
• PVC tubing comes in different types such as:

  • PVC 70
  • PVC 120
  • Clear PVC