Exploring Sickle Cell Anemia in Individuals X, Y, Z

Do individuals X, Y, Z have Sickle Cell Anemia or Sickle Cell trait? In this investigation three DNA samples were tested to see if they had Sickle Cell or carry the Sickle Cell trait. Sickle cell Anemia is a disease of the red blood cells that is inherited from your parents. Sickle Cell is caused by point mutation in which a single base in the ꞵ-globin gene that results in the substitution of valine instead of glutamate in the amino acid chain. The acid change aggravates the blood cells and make them take a sickle shape and lose elasticity. The main purpose of Hemoglobin is to carry oxygen from the lungs to the body’s tissues. To carry out this function a healthy red blood cell has a hollowed circular cavity which allows them to hold nutrients

As stated earlier, Sickle cell Anemia is caused by a point mutation in the ꞵ-globin gene that changes an Adenine base into a Thymine base. The enzyme used in the experiment is Bsu36 I which recognizes the sequence CC/TNAGG (N= any nucleotide). That sequence is present in the coding for a normal hemoglobin, but not in a cell affected by Sickle cell Anemia. When the restriction enzyme recognizes the enzyme it is looking for, it splits the DNA in two parts at the specified location or otherwise does nothing to the sequence. Six DNA samples are used total, two from each individual, each marked cut or uncut. Every sample is mixed with 2.5 µl of 10X Buffer E and 2.0 µl of BSA ( Bovine serum albumin). The uncut samples act as a control and are mixed with 1 µl of water. All of the cut are mixed with 1 µl of Bsu36I. Samples are then put in the centrifuge to evenly distribute and then placed in the hot block at 45 degrees Celsius. During this incubation, period an 0.8% agarose gel suspended in 1X TAE buffer was prepared for electrophoresis. In each window of the gel, the samples (X, Y, Z) are aligned in the following order; Xu, Xc, Yu, Yc, Zu, Zc (u= uncut, c= cut). DNA has a negative charge, so during electrophoresis a positive charge is lined up on the same side as the samples to push them out into the gel. The negative charge

The gel chart below shows the correct number of bands to correspond to the claim but the band widths were inconclusive. The reason why the band widths were incorrect was probably because of human error during the procedures. The first sample on the chart is X. The two bands present suggests that individual X probably does not have any Sickle Cell genes because the cut samples resulted in two bands while the uncut stayed as one. This was a result of the uncut sample, without the restrictive enzyme, being a sample of Sickle Cell free blood cells. In addition, the cut sample of X, split into two bands meaning that the sample also consisted of Sickle-free cells. Because both of the samples were free of Sickle cell, the X individual did not suffer from Sickle Cell, nor were they a carrier. Samples from individual Y both produced one band. Therefore this donor probably had Sickle Cell anemia, because the restrictive enzyme Bsu36I does not cut the sequence of mutation Sickle Cell causes. The last sample, Z, shows up as one band for the uncut sample and three bands for the cut sample. Thus, the Z individual is a carrier of Sickle Cell but does not suffer from the symptoms themselves. The reason individual Z does not necessarily suffer from the symptoms of SCA is because it is an autosomal recessive disease. An autosomal recessive disease must have two copies of the