Report 8: Red Blood Cell

INTRODUCTION

Red blood cells have certain proteins on their surface called antigens. Also, plasma contains antibodies which will attack certain antigens if they are present. There are various types of red blood cell antigens - the ABO and rhesus types are the most important.

These were the first type discovered.

• If we have type A antigens on the surface of our red blood cells, we also have anti-B antibodies in our plasma.
• If we have type B antigens on the surface of our red blood cells, we also have anti-A antibodies in our plasma.
• If we have type A and type B antigens on the surface of our red blood cells, we do not have antibodies to A or B antigens in our plasma.
• If we have neither type A or type B antigens on the surface of our red blood cells, you have anti-A and anti-B antibodies in our plasma.

Most people are 'rhesus positive' as they have rhesus antigens on their red blood cells. But, about 3 in 20 people do not have rhesus antibodies and are said to be 'rhesus negative'.

Blood group depends on which antigens occur on the surface of our red blood cells. Genetic make-up which we inherit from our parents determines which antigens occur on our red blood cells. Because of this fact a blood group test is sometimes used to help settle disputes about who is the father of a child.Blood group is said to be:

• A+ (A positive) if you have A and rhesus antigens.
• A– (A negative) if you have A antigens, but not rhesus antigens.
• B+ (B positive) if you have B and rhesus antigens.
• B– (B negative) if you have B antigens, but not rhesus antigens.
• AB+ (AB positive) if you have A, B and rhesus antigens.
• AB– (AB negative) if you have A and B antigens, but not rhesus antigens.
• O+ (O positive) if you have neither A nor B antigens, but you have rhesus antigens.
• O– (O negative) if you have do not have A, B or rhesus antigens.

Basically, a sample of our blood is mixed with different samples of plasma known to contain different antibodies. For example, if plasma which contains anti-A antibodies makes the red cells in your blood clump together, then we have A antigens on our blood cells. Or, if plasma which contains rhesus antibodies makes the red cells in our blood clump together, then we have rhesus antigens on our blood cells. By doing a series of such tests it is possible to determine what antigens are on our red blood cells and therefore determine our blood group.

Routine blood grouping checks for our ABO and rhesus status. Other red cell antigens are tested for in certain other situations.

A blood group test is always done on pregnant women. If the mother is rhesus negative, and the unborn baby is rhesus positive (inherited from a rhesus positive father), then the mother's immune system may produce anti-rhesus antibodies. These may attack and destroy the baby's blood cells. This is rarely a problem in a first pregnancy. However, without treatment, this can become a serious problem in subsequent pregnancies as the mothers immune system will be 'sensitised' after the first pregnancy.

LEARNING OUTCOMES

In this experiment, we are able to determine

• Our own blood type with respect to the A and B antigens.

MATERIALS

• Slide
• Sterilizer
• Lancets
• Swabs
• Toothpicks
• Container for swabs disposal
• Antisera
• 70% ethyl alcohol
• Anti-A (a) serum
• Anti-B (b) serum

METHODS

Two glass slide for each students was prepare. The slide must be clean. The slide was mark at the end with a letter “A” and other end “B”. the other slide was mark with letter “C”

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Carefully we wash our hand by using the soap detergent supplied and then blotted with a dry clean paper tissue. Then left index finger was swab with a sterile cotton swab dipped into 70% alcohols.

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Quickly the sterile disposable lancet was remove and was quickly prick on the tip of the finger. The lancets were disposed.

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The lanced finger was massage and squeeze out 3 drops of blood into each glass slide.

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At the glass slide with letter ”A”, put antisera A

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At the place with letter “B” put antisera B

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At the other slide with letter “C” put the anti-D

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A clean toothpick was use to mix the blood with the antisera. Different toothpick was use for different antisera. Lastly, the toothpick was disposable.

The sera you have used are color coded. What color is the serum containing alpha antibodies?

Yellow

What color is the serum containing the beta antibodies?

Blue

Place the slide on a piece of paper and observe. What do u see?

I have see that my blood become agglutination with anti-B only.

What is your blood type, with respect to the A and B antigen? Did you know your blood type before this test?

My blood type is type B and respect to anti-B only. Yes I know my blood type.

Does your determination agree with what your medical record indicates?

Yes

RESULT

My own blood type      : B

Antigen on RBC’s      : B

RH⁺ test                        : Positive

DISCUSSION

                                From the experiment, we already known our blood type. I have blood B+. means that I have antigen B and antibodies A with rhesus positive. How do I know that my blood is type b? this is because when a drop of my blood was put on the slide, then put a drop of anti a and anti b, my blood will agglutinate with anti b and for the rhesus test, my blood will agglutinate with anti d and it show the positive result..For blood A type, the blood will agglutinate with anti A , while if there are no agglutination means the blood is O type. If both are agglutinate, means that it is AB blood type. Blood type is control by multiple allele. Multiple allele is more than 1 allele ate the same loci.

CONCLUSION

                             As a conclusion, we are able to apply the sterility in the lab before identified the blood type of myself and my friends. Other than that, we also learn how to use the disposable lancets.

REFERENCES

Brooker, R. J. (2009). Genetics Analysis & Principle. Third edition: Mc Graw Hill Companies Inc.

Campbell O.N. (2005). Biology. Seventh Edition: Benjamin Cumming.

Eldra P. S., Linda R. B. and  Diana W.M. (2005). Biology. Third Edition: Thomson Brooks/Cole.

Kenneth R. M.,and Joseph L. (2004). Prentice Hall Biology. Teacher's Edition: Pearson Publishing.