There are two types of somatic cell nuclear transfer (SCNT).

Reference: https://www.thoughtco.com/cloning-techniques-373338

PCR

Now that you've identified the mammoth's gene of interest (e.g. haemoglobin), you know the sequence you need to isolate. You should use the technique called PCR (polymerase chain reaction), to isolate this specific gene sequence.

• Step 1: Denaturation (95°C) - to separate DNA into single strands.

• Step 2: Annealing (55°C) - specific primers you designed to target the gene sequence will bind to the correct complementary sequence on your single stranded DNA.

• Step 3: Extension (72°C) - Taq polymerase extends the DNA primers by adding bases using the complementary base pairing rule.

Steps 1-3 are repeated many times, to amplify this specific gene sequence.

Gel Electrophoresis

Now that you have amplified your mammoth gene sequence from the rest of the mammoth DNA, you've got to purify it to cleanse it from the other substances involved in the PCR reactions. These other substances include other DNA sequences, primers, enzymes, and other reagents. You will purify your gene sequence using gel electrophoresis.

This technique separates DNA sequences according to size. Size is measured using a 'DNA ladder; as a reference. When you've separated your gene of interest from the rest of the DNA

Gel electrophoresis https://www.addgene.org/protocols/gel-purification/

Sanger Sequencing / DNA Sequencing

Four reaction tubes are created, all with a small sample of your purified DNA.

• ddNTPs for adenine is added to tube 1

• ddNTPs for thymine is added to tube 2

• ddNTPs for cytosone is added to tube 3

• ddNTPs for guanine is added to tube 4

You run each tube through the steps of PCR, but instead this time, ddNTPs are randomly added throughout the sequence. For example, in tube 1 instead of DNA polymerase pairing dNTP of adenine to a thymine, it randomly adds a ddNTP of adenine to the thymine.

Once the ddNTP is added, the sequence is terminated, and DNA polymerase can no longer extend that strand of DNA. This results in a sample of DNA fragments of different lengths.

Samples from all 4 tubes are run on a gel, and DNA fragments are separated by length via gel electrophoresis. The sequence is read from in the direction of the shortest fragment to the longest fragment.

OR another way is to run the negatively charged DNA in a capillary tube. They separate according to size, and are read one by one as the ddNTP fluoresces a unique colour.