1 QUALITY ASSURANCE Quality Assurance of Reagents, Supplies, And Laboratory Water
2 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 2
3 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 3
4 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 4
5 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 5
6 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 6
7 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 7
8 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 8
9 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. 9
10 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 10
11 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 11
12 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 12
13 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 13
14 Laboratory Water Purification of water can be achieved through 3 methods: Distillation Deionization Reverse osmosis Additional purity is obtained with charcoal filtration. 14
15 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 15
16 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 16
17 Three of Clinical Laboratory Water 17