QUALITY ASSURANCE Quality Assurance of Reagents, Supplies, And Laboratory Water.
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Transcript of QUALITY ASSURANCE Quality Assurance of Reagents, Supplies, And Laboratory Water.
QUALITY ASSURANCEQuality Assurance of Reagents, Supplies, And Laboratory Water
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• In order to produce high quality work, a laboratory requires a constant supply of good quality reagents, supplies and water
• A deficiency of any of these can cause the most efficient laboratory either to come to a standstill or to provide substandard service
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Choice and Evaluation of Reagents and Supplies
• A selection of a brand of reagent for instrument system or laboratory tests is made after searching and gathering information concerning the reagent sensitivity, preparation, storage, and cost
• Next, an evaluation of the selected material is performed in the laboratory, comparing the new reagent to the old
• If the comparison is favorable, the new reagent is purchased
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Choice and Evaluation of Reagents and Supplies
• Before committing to purchase insists on performing a field trial of the reagent
• Factors that should be considered in selecting and evaluating a new reagent or material supplies are: 1. Sensitivity
2. Stability and storage conditions
3. Vendor reputation
4. Delivery time
5. Cost
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Laboratory Inventory Management • Effective inventory control involves setting up a system that has the following goals: • Simplify and reduce paperwork• Improve communication between the laboratory and the
other hospital departments involved in purchasing, stocking, and paying for supplies
• Manage inventory so that Shortages and overstocking should be avoided
• Teaching laboratory employees better budgeting and materials management techniques
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Inventory Control Program
• Designing and implementing an inventory control program involves :• The identification of the needed supplies• Their rate of use• Periodic review and evaluation of the inventory and
ordering process
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Inventory Control Program
• Conduct a survey to list all of supplies that the laboratory uses, the list should include: • The name of the item• A brief description • Approximate usage per month • Current vendor • Order unit amount • Current unit packing, that is per box, carton, or bag• Order or catalogue number • Priority of need
• Assigning an item its relative importance• High priority: if needed constantly or cannot be done without• Medium priority: if needed occasionally• Low priority: if needed rarely
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Inventory Control Program
• The next step is to determine the order point, order quantity and lead time for the item
• Order point: the sum of the minimum inventory plus the emergency supply• The level of inventory at which an order is generated
• Lead Time: is the length of time between initiating an order and receiving it in the laboratory
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Inventory Control Program
• Controlling inventory involves the counting, storage and movement of supplies within the laboratory
• A written record system of inventory levels and checks should be devised
• Three types of record systems are suggested: 1. The periodic count
• Strict inventory control is not required• Count of materials weekly or every two weeks, when count
reaches the order point, an order is generated• Good for small to midsize Lab.
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Inventory Control Program
2. The perpetual inventory record • Strict inventory control is required• Inventory is closed to lab. Personnel, one or two persons
manage it• Good for larger lab.
3. The specialized inventory record • Used for slow-moving, infrequently ordered parts such as
instrument spare parts• Parts are not ordered until inventory is used
• Once the inventory system has been set up, it should be reviewed annually for updating
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Reagents Prepared in the Lab.
• Reagents, standards and controls prepared in the laboratory from stock chemicals should be:• Prepared using class A volumetric glassware and
properly calibrated balances• To eliminate variation (batch to batch), preparation should be
limited to one or two persons
• Label each reagent, standard, and control with the following: • The name of the material • The procedure for which the material is to be used • Date of preparation • Date of expiration • Initials of the person who prepared it
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Laboratory Water
• Reagent - grade water must be properly purified and periodically inspected for: • Electrical resistivity
• Resistivity (R) of water is the measurement of electrical resistance and is the inverse of electrical conductivity (C)
• R and C are directly related to the number of inorganic ions and conduction particles in the water
• The greater the ionic concentration, the greater the electrical conductivity and the less the electrical resistance
• Measurements are made using a resistivity or conductivity meter
• Soluble silica concentration • measured by a chemical reaction between silicate and
molybdate ions to form a blue complex
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Laboratory Water • Desired pH
• The pH is measured with pH meter• Bacterial contamination
• The microbiological content of the water is defined as the number of colony - forming units per milliliter of water
• Three recommended methods:• Pour plate (1 ml of water)• membrane filtration • or calibrated loop for sampling (0.01 ml)
• If organic free water is desired , soluble organic materials can be removed using charcoal filter
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Laboratory Water • Purification of water can be achieved through 3 methods:
• Distillation • Deionization • Reverse osmosis
• Additional purity is obtained with charcoal filtration.
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Water Grades According to Purity
• Type I water: • The highest level of purity, • used for:
• tissue and cell culture methods• special and critical analytical chemical analysis• and in preparation of standard solutions
• Type II water: • Used for most routine quantitative clinical laboratory
methods• It should be stored for short periods of time before use,
to prevent change in resistivity and bacterial growth
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Water Grades According to Purity
• Type III water: • The least pure • Suitable for most qualitative procedures including:
• Urine analysis • parsitology • and histology
• Suitable for glassware washing • Stored in containers that protect it form contamination
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Three of Clinical Laboratory Water