Practice Assignment 02
Blood cell check-up
The two standard procedures listed can be used directly for this assignment. A small amount of suitable blood is needed. Samples of fresh pig’s blood might be obtained from a local butcher. An anticoagulant such as heparin should be added to stop it clotting. Alternatively treated mammalian blood is available from biological suppliers.
Some students could be encouraged to distinguish between different types of white blood cell and to try to find platelets in the blood smears.
Health and safety note
When handling blood, students should wear protective clothing, including disposable gloves, and must take suitable precautions, including washing hands afterwards. They should be shown how to dispose of used slides, pipettes and cover slips appropriately.
Apparatus and reagents
- Standard Procedures:
- SP 0001:2005 Methods for setting up and adjusting a light microscope
- SP 0002-2:2005 Methods of preparing slides for microscopy – Part 2: Preparing a blood smear
- microscope with two or more objectives
- pre-prepared specimen slide (e.g. microdot - Philip Harris catalogue item C5A76090)
- light source (lamp or good daylight)
- specimen of fresh animal blood (See above.)
Caution: possible biohazard - 2 microscope slides and a cover slip
- disposable dropper
- hair dryer or bench lamp
- 4 glass staining pots (or 100 cm3 beakers)
- forceps
- methanol
Caution: highly flammable and toxic - neat Leishman’s Stain (1.5% solution in methanol)
Caution: highly flammable, toxic, stains skin and clothing - dilute Leishman’s Stain (neat Stain diluted 1:10 with water buffered at pH6.8)
Caution: harmful, stains skin and clothing - mountant e.g. DPX
Caution: contains xylene (dimethylbenzene) – harmful, irritant. Available from BDH Chemicals (VWR International, Poole, BH15 1TD. Tel: 01202 669700. Website: www.vwr.com) .