There will be no report on this experiment, but this material will be covered on the final
You will be required to do the following four tasks and fill in the chart on page 121. Set up the lab table as you found it before leaving. All sharp objects (the plastic Unopette capillary tubes, the glass capillary tube, the lancet, and the both microscope slides) should be placed in the red plastic sharps container and anything that is not sharp and may have blood on it must go in the plastic bag on your lab bench for incineration. If you are not sure, just put any thing that could accidently puncture the plastic bag into the sharps container. Replace all the used eqiupment with new supplies from the front table. Supplies you will use are listed and described on pages 118 to 121 in your lab manual. Wash hemocytometers and the cover slip that goes with it in a 10% bleach solution.
Only the T. A. is allowed to prick your finger. Don't do it yourself, because it takes two people to prep the tests you are requied to do. Don't let your lab partner prick your finger for safety reasons.
1. Hematocrit: Fill a capillary tube at least 3/4 with blood. Once filled, hold the tube horizontal so that the blood does not run out of the end due to gravity. Plug one end with your finger when inverting the tube to stick it in the clay. Be careful not to break the tube and cut yourself with it. Remember which number is next to your tube so that you can identify it later. The TA will come by to pick it up and centrifuge it for you. The TA will demonstrate how to determine % hematocrit. For males 40-45% is considered normal, for females it will be from 35-40%.
2. Differential: Put a drop of blood on one end of a glass microscope slide. Use the other slide to grab and pull the drop across the slide before it begins to clot. You want the smear to be one cell thick for the best visiblilty. Allow the slide to air dry then fix and stain it as described by the TA. On this slide you need to identify 100 leukocytes and determine which type they are. Once you have identified them you will have a rough estimate of the percentage of each in your blood, i.e. if 7 of the 100 cells were Monocytes, they are about 7% of your total leukocytes. The expected values are as follows:
Leukocyte Type, Normal range (% of WBCs), Increases due to, Description
Neutrophils, 40-60%, Bacterial infections, Medium size, purple, granules
Eosinophils, 3-6%, Parasitic infections, allergies, asthma, Like neutrophils w/pink grains
Basophils, 0-1%, Allergic responses, Like neutrophils blue granules
Monocytes, 4-9%, Chronic infection, Largest, no granules
Lymphocytes, 20-40%, Viral infections, Small, slightly larger than a RBC, no granules
You can distinguish these from each other and from red blood cells easily by size, stain color, abundance and comparison.
3. WBC Count: Fill the Unopette (#20 yellow) capillary tube as described on page 118-119. The solution in the unopette base will lyse all the RBCs so that you can count the WBC easily. Load the hemocytometer as described and count the cells on the entire grid (pictured on pg 120). Use the worksheet to calculate number of cells per cubic mm. [(# counted X 10% of count)+ # counted]. The range should be from 5,000 to 10,000 cells/mm3. The most common errors are improper loading of the unopette or hemocytometer.
4. RBC Count: Fill the Unopette (#10 pink) capillary tube as described on page 118-119. The solution in the unopette base will lyse all the WBCs so that you can count the RBC easily. Load the hemocytometer as described and count the cells on the diagnal center grid (labeled with "R" on the grid on pg. 120). Use the worksheet to calculate number of millions of cells per cubic mm. (# counted X 10,000). The range should be from 4.6 to 6.0 million cells/mm3. The most common errors are improper loading of the unopette or hemocytometer. Use the manual counter so you won't loose count.