Cleaning and Storing of Microscope Slides

Ensure the availability of clean, good quality glass slides for the preparation of blood specimens for microscopic examination;

Ensure that the microscope slides are properly cleaned, stored and readily accessible in all microscopy centers;

Ensure that the following materials and supplies are available for the cleaning and storing of microscopy slides;

i. frosted glass slides 

ii. plastic bowls or basins 

iii. good quality detergent (liquid or powder) 

iv. washing cloths or soft sponges 

v. clean, lint free cotton cloths (the kind used to dry glassware) 

vi. a good supply of clean water 

vii. sheets of clean paper cut to 11 cm. x 15 cm in size 

viii empty slide boxes 

ix. clear adhesive tape 

x. dessicators or activated silica gel

Observe the following procedures in cleaning and storing the slides

a. Cleaning and storing of Slides 

All slides must be thoroughly clean and free from scratches, grease or moisture. This will prevent most of the artifacts which may confuse malaria diagnosis and will avoid the detachment and washing away of thick blood films during the staining process. Poorly cleaned slides will lead to sub-standard blood films, in turn leading to imprecise microscopy. Gloves must be worn when washing microscope slides.

New slides

i. Remove slides from the box and place individually in a basin of warm detergent solution and soak for 2-3 hours preferably overnight; 

ii. After soaking, use the washing cloth or sponge to clean each slide on both sides by rubbing the two surfaces of the slide between the forefinger and thumb; 

iii.Rinse slides individually in clean water to remove all traces of detergent. This may require two bowls; 

iv. Handle slides by the edges to drain the excess water from each slide before drying thoroughly with a clean, lint-free cotton cloth; 

v. Although the slides are new, discard any chipped and scratched slides which are unsuitable for hematology. They may be used for medical entomology activities; 

Using the cut paper pieces, wrap the dried slides in packs of ten. Turn down the ends of the wrapper and secure with clear adhesive tape. Place the slides in the cardboard boxes ready for use. Keep each box secure with a rubber band.

Used slides

i. You may reuse slides after slide validation if still in good condition; 

ii. Place individually the used slides in a basin of warm detergent solution and soak overnight; 

iii. Clean one by one with a washing cloth or soft sponge until all traces of the blood film and oil have been removed; 

iv. Transfer the slides to a fresh solution of good quality detergent and later to running water or several changes of clean water handle the slide by the edges to drain the excess water; 

v. Dry the slides thoroughly with clean, dry and lint free cloth; 

vi. Using the cut paper pieces, wrap the dried slides in packs of ten. Turn down; the ends of the wrapper and secure with clear adhesive tape. Place the slides in the cardboard boxes ready for use. Keep each box secure with a rubber band.

b. Storing and Discarding of Slides

i. Glass slides should not be kept in room temperature of the humid tropics for more than a few weeks. Otherwise they will adhere to each other due to entrapped moisture and there will be a loss of transparency due to ‘frosting’; 

ii. It is recommended that cleaned slides be stored in packages of 10 which have been wrapped in thin paper and secured with cellulose adhesive tape or rubber bands so that they are ready for use; 

iii. Packages of slides can be put in the original cardboard boxes or other suitable boxes with desiccant; 

iv. Slides with the following conditions must be discarded and stored in a puncture – proof container: (i) with scratches, (ii) chipped, or (iii) blue color glass slide. 

v. Used slides can be disposed in any of the following: (i) septic tank, (ii) burial pit, or (iii) cemented vault in accordance to the DOH Healthcare Waste Management Manual (2004);

Source:  Department of Health - Malaria Control Program Manual of Procedures, Guidelines in the Diagnosis and Treatment of Malaria