Gel electrophoresis is a type of technology that separates compounds based on their size.A strand of DNA is separated from a source and then suspended in a dye.The gel is applied to one side of the sheet.The positively-charged gel on the other side of the sheet is reached by the DNA through a set of horizontal stripes.It is helpful to determine relatedness between two or more species.It can be used to create a DNA fingerprint.
Step 1: If you hold a UV light up to the gel sheet, you can see the results.
The switch on the tube of UV light is located in front of you.The UV light is away from the gel sheet.To read the results, illuminate the samples with the UV light.If the test went well, your sheet should have a number of stripes in parallel rows.You can skip this step if you read the results on a sheet of paper.UV-light isn't required for some stains.Check which stain you used and how to see it, for example, some dyes can be activated by blue light, or are readily visible without need for any special lights.
Step 2: To find the wells, look for the biggest pools of color.
The original location of the samples is called the wells.There is a big pool of colored gel at the end of your sheet.The wells are the locations where the gel samples are loaded into the sheet.Each sample should have one well.The sample may have been applied poorly if one of the wells is lacking color.The negative end of the sheet can be seen on the wells.The positive end is on the opposite side of the sheet.The negatively-charged DNA travels across the sheet to the positive pole when a sample is applied.
Step 3: Classify each strip by the origin of the samples.
If you have been given a key, you should know that each horizontal row depicts a unique set of DNA.Determine what each row is by using your key.The number of samples can be determined by counting rows.You cannot determine the source of each sample if you don't have a key.It doesn't reveal the source of a sample on its own, but it provides you with information about it.If you did the test on your own, you should write down where each row is from.
Step 4: To establish a scale for the DNA, you need to identify the ladder.
Depending on whether or not a DNA ladder was included in the test, you may have one strip designed to provide you with a scale to make comparisons easier.The scale is called the DNA ladder.To make it easier to figure out how big or small the other strips are, the DNA ladder will have strips of known sizes.There will be a lot of variation in the sequence of the strips.There may be a few thin strips, followed by thick strips and ending in more thin strip.It's easier to figure out how big the individual strips are by comparing them to the DNA ladder.The last row at the top or bottom of your sheet is where the DNA ladder is usually placed.
Step 5: The smaller DNA molecule can be found on strips further from the wells.
When each sample is applied, it starts moving away from the negative pole towards the positive pole because it is negatively charged.This isn't what causes the molecule to separate.Larger DNA molecules are slower because they have more mass to move, but they also experience a higher force from the electric field because of their negatively charged phosphate groups.Two people cancel each other out.The resistance that the sample molecules experience from the gel is what causes the separation.When the gel electrophoresis is stopped, smaller Molecules can migrate through the pores of the Gel, so they will have traveled further.
Step 6: The slower DNA can be found by looking at the strips closest to the wells.
When the electrophoresis is stopped, large molecule will migrate more slowly through the pores of the gel, so they won't have traveled as far as a shorter molecule.If you look at the frequencies of the bigger and smaller strips in a row, you can see the sample's fingerprints.Each genetic sample has its own way in which individual strips are arranged.A picture of someone's genetic makeup is created by the pattern of strips.The thickness of each band is not an indication of how long the DNA molecule is.
Step 7: The size of each strip can be determined using the DNA ladder.
You can use the ladder to compare the individual strips.The size of the strips in a DNA ladder depends on the type of ladder used for the test, but usually it is 10 to 100 bp.The strip furthest from the wells is the lowest in the spectrum.The one closest to the wells is 100 bp, and the one furthest is 10 bd.The same as 1 kb is 1000 bp.The ladder may use this unit instead of bp because Kb is short for kilobase.The smaller the scale, the more accurate the comparisons will be.The units of measurement are base pairs and kilobases.They refer to the size of the molecule.
Step 8: To find similarities, look for strips that appear at the same point.
When looking at the entire sheet, look for points where 2 or more strips are in the same place.This is a sign that the samples are related.If there are more than 2 rows without overlap, they are unrelated.The more samples are related, the more overlap there is.If you are looking at the sheet with the wells on the left, you want to see vertical columns where 2 strips appear at once.A mother and her child have half of their strips overlap.A child and their cousins may only have a few strips that overlap.
Step 9: Find strips with the same configuration to identify identical samples.
Two or more samples have the same sequence of strips.The source of the sample may be different for identical twins, for example.It's usually necessary to tie a suspect to a crime scene with identical strips.
Step 10: Understand the limitations of the test.
It can be hard to make a conclusive conclusion when comparing DNA samples.The scale can get so big that it can make bands hard to see.You will not be able to say that 2 samples are related.There is a strong similarity between 2 samples.Scientists say that there is a high probability that 2 samples are related if less than half of the bands overlap.