Diagnostic tests - Practical guide to testing
To prevent bacterial contamination
- - Apply free falling drops (do not allow the bottle to touch specimen)
- - Close the bottle tightly after use
Write on the box of the kit or on the bottle, date of opening as the expiry date might change from the one printed on the box when reagents have been opened.
Always check storage temperature for reconstituted or opened reagent, as it can be different from that of an unopened reagent.
When different strengths of external controls are included in a kit and if the stoppers are identical, mark on the top of each stopper a different sign/symbol to avoid cross-contamination. Examples:
"-" for non reactive control
"+" for weak reactive control
"++" for strong reactive control
Internal controls help to see if the sample has been added and/or to detect deficient tests: Internal controls do not prove that the reactive area is still reacting with the particular antigen or antibody being looked at.