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