Characteristics of Different Blood Types Experiment

Experiment 3- Blood II

Rezan Nehir MavioÄŸlu, Tara McDermott, Yasemin Barış, Dogan ÇolakoÄŸlu

Introduction

In this lab, we took our own blood samples and observed the presence and characteristics of our white blood cells, and our specific blood type. Through this experiment, we determined the number of white blood cells present in 1mm3 of blood, the different types present, and our unique blood types.

Before performing the experiment, we knew (collectively) white blood cells protect the body from foreign invaders and pathogens. The body’s defense mechanism via white blood cells is either innate (reacts with low specificity to foreign pathogens) or acquired (antigen specific response). In this particular lab, we identified eosinophils (granulocyte/phagocyte), neutrophil (granulocyte, phagocyte), macrophages and monocytes (phagocytes), and lymphocytes (cytotoxic cells) within our blood. White blood cells are classified by staining procedures (we used Wright’s stain to identify WBC’s based on intracellular pH) or by the presence of cytoplasmic granules. Granulocytes contain cytoplasmic granules, phagocytes ingest foreign invaders, and lymphocytes comprise part of the acquired immune system.

Blood type is determined by the presence of extracellular antigenic “markers” on the surface of a cell membrane. The blood types are as follows:

A: only A antigens of red cells

B: B antigens extracellular

AB: both A and B antigens extracellular

O: neither A or B on surface

Individuals with A carry antibodies for B, type B carries antibodies for A, and type AB carries no antibodies to A or B. Type O individuals carry antibodies for both A and B.

Additionally, there is a third factor called “Rh factor”, which is either present (+) or absent (-) on the surface of a cell. Rh + individuals can receive both + and – blood, but Rh – individuals can only receive Rh – blood. Thus, Type O- is referred to as the universal red cell “donor”.

We determined our blood type by adding anti A, anti B, and anti D antibody solutions to each of our blood samples and observing the coagulation. For example, if a blood sample coagulates where anti A is added, and where anti Rh is added, then the individual’s blood type is A+.

Materials and Methods

Materials- Experiment 1: Total White Blood Cell counts

Blood (taken from experimenters)

Lancet

Microscope

Hematocytometer (for samples)

Turck’s solution (for staining white blood cells’ nuclei)

Method: We lanced our finger, taking about 5 ul of blood and mixing it with 95 ul of Turck’s solution to stain the nuclei of our cells- so as to only identify white blood cells. We took 20 ul of this 1:20 dilution and filled the hematocytometer. Using a lowe power objective, we counted all visible nuclei within 18 squares of the counting chamber.

Materials- Experiment 2: Differential White Blood Cell Types

Lancet

Blood

Clean Glass slides

Wright’s stain (to identify white blood cell types based on pH)

Microscope

Method: Taking another drop of blood, we added it to a glass slide and covered it, allowing it to dry. We added Wright’s stain and incubated for about 2 minutes, adding additional stain to keep the sample from drying out. After rinsing the slide with water and allowing it to dry, we observed the sample under a microscope. Based on pH differences, presence of intracellular granules, and shape of nuclei, we counted and classified 200 white blood cells.

Materials- Experiment 3: Blood Types

Blood

Lancet

Glass slide

Anti A, Anti B, and Anti Rh (D) serum

Method: We placed three drops of blood on a glass slide, and added the anti solutions to each. After smearing and allowing time for coagulation, we observed the samples to determine blood type.

 Results

Total WBC counts

White blood cell counts were obtained from the number of WBCs in 16 squares of hemocytometer. 16 squares have a volume of 0.1 mm³ and the blood samples were diluted 1:20. Therefore, total WBC counts in 1 mm³ was calculated by multiplying the observed number by 200. Please see Table 1 for WBC counts per mm³ for each group member.

Histogram of WBC counts of a sample of 40 males and 40 females can be seen in Figure 1. Independent samples t-test revealed that there were no gender differences in mean WBC counts (p=0.86). Descriptives for WBC counts can be seen in Table 2. According to the table, DoÄŸan and Yasemin are in the last percentile, and Tara and Nehir exceed the maximum value.

Figure 1: Histogram of WBC counts of sample group, with normal curve

Table 1: Observations and measurements for each group member

 Differential white blood cell counts

Please see Table I for differential WBC counts in percentages for each group member. DoÄŸan and Yasemin has neutrophil as dominant WBC, whereas Nehir has lymphocyte and Tara has monocyte & macrophage.

Blood Types

For Nehir, Yasemin and Tara, only anti D serum formed aggregate. For DoÄŸan, only anti A serum formed aggregate. Please see Table I for blood groups of each group member. Percentages and frequencies for each blood type can be seen in Table 3. Distribution of blood types according to the sample data can be seen in Figure 2.

Table 3: Frequencies and percentages of each blood type

Figure 2: Distribution of blood types

Discussion

The aim of this experiment was to measure the WBC counts, observe the different types of WBCs and see the distribution among them, and determine our blood type by coagulation reaction by anti A-B and D serums.

The first part of the experiment was measuring WBC counts. Only DoÄŸan and Yasemin were in the normal range according to sample data provided. According to NIH, normal WBC range is from 4500 to 10000. Therefore, Yasemin is just slightly above the range, and Tara and Nehir were definetely above the range. This result may be due to anemia, infections or an inflammatory disease. Drugs, some diseases, and radiation may also affect WBC count.

The second part of the experiment was to observe different cell types. Neutrophil was dominant for DoÄŸan and Yasemin, lymphocite was dominant for Nehir and monocytes & macrophages was dominant for Tara. Neutrophil should be the dominant cell type in blood, so we can say that DoÄŸan and Yasemin were healthy during the experiment day. High lymphocyte number is an indication of hepatitis, mononucleosis, leukemia, viral infections, and bacterial infections. Nehir might have caught flu (we hope). An increased number of monocytes indicate inflammatory disease, leukemia, or viral infections. Tara may have viral infections. Apart from that, none of us could not count 200 cells as we supposed to do. Therefore, these results may be misleading.

The last part of the experiment was to determine the blood types. DoÄŸan has A Rh -, and the rest of the group has 0 Rh + type of blood. This result does not fit the distribution shown, with A Rh + dominancy. (see Figure 2 and Table 3). However, 4 people is not enough to prepare a statistics and obtain meaningful results. Ethnicity seems to be a major component of blood type variation among different countries. Pure ethnic groups might have specific blood types due to genetics and geography.

References

1. Lab manual

2. Silverthorn, Dee U., et al. Human physiology : an integrated approach. Boston: Pearson Education, 2013. Print.

3. Hardy Diagnostics. “Wrights Stain.” Hugo. Hardy Diagnostics, n.d. Web. https://catalog.hardydiagnostics.com/cp_prod/content/hugo/OneStepWrightsStain.htm.

4. Red Cross. “Blood Types.” American Red Cross. American Red Cross, n.d. Web. http://www.redcrossblood.org/learn-about-blood/blood-types.

5. Blood Book. “Racial & EthnicDistribution of ABO Blood Types” http://www.bloodbook.com/world-abo.html.

6. National Institues of Health. MedlinePlus. “WBC count.” http://www.nlm.nih.gov/medlineplus/ency/article/003657.htm

7.National Institues of Health. MedlinePlus. “Blood differential.” http://www.nlm.nih.gov/medlineplus/ency/article/003643.htm