Lab 1: Blood 

     To look at blood cells you need to use the oil immersion objective (100X). First focus on the objective using the scanning objective. Then move to the 20X lens, refocus and then turn to the 40X objective and again use the fine focus to sharpen the image.

     Now move the high dry lens out of the way and place one drop of immersion oil on the slide over the specimen. Swing the 100X objective into place so that it goes into the oil. If you had the slide in focus on 40X then the immersion oil objective won’t hit the slide but it will get very close (parfocal). Use only the fine focus to bring the specimen into sharpness with the 100X lens down.

     You may move the slide about. The drop of oil is plenty for looking around. When you are finished, wipe everything with oil on it off! You can use Windex and Kleenex on the slide and use alcohol and lens paper on the oil objective and the high dry objective.
 

A. Blood Cells 
     You will now start to use the slides with the yellow labels on the bottom shelf, box B. 
 
1. Slide 8B (blood smear)
Using the oil immersion lens find – erythrocytes (red blood cells) --- thrombocytes (platelets) --- lymphocytes --- monocytes --- eosinophils --- neutrophils --- basophils.
 
2. Plaster-of-Paris models of formed elements
Be able to recognize the models of – small lymphocyte --- large lymphocyte --- monocyte --- neutrophil --- eosinophil --- basophil --- thrombocytes (platelets) with fibrin --- erythrocyte (RBC).