② Primers in ②②PCR technology are essentially single-stranded DNA fragments or RNA fragments.
③ In ③PCR technology, the principle of opening DNA double helix structure is to control the depolymerization and combination of DNA molecules by controlling temperature. When the temperature is 95℃, DNA molecules denature and the double helix structure opens, forming two single strands.
④ Primer extension means that the synthesis of DNA molecules needs four kinds of free deoxynucleotides as raw materials.
(2)① Sample treatment in the process of hemoglobin extraction and separation includes washing red blood cells, releasing hemoglobin and collecting hemoglobin solution.
② The coarse separation process refers to the process of dialyzing the collected hemoglobin solution in a dialysis bag. The principle is that the dialysis bag allows small molecules to enter and exit freely, while the large molecules remain in the dialysis bag. After dialysis, impurities with small molecular weight are removed.
③ The purpose of further purifying the sample by gel chromatography is to remove impurity proteins with relatively large molecular weight.
So the answer is:
① denaturation, renaturation and extension ② single-stranded DNA or RNA? ③ The double-stranded DNA heated to 95℃ was separated into two single strands and four kinds of deoxynucleotides.
(2)① washing of red blood cells and release of hemoglobin
(2) Removing impurities with relatively small molecular weight can make small molecules enter and leave freely, while large molecules remain in the dialysis bag.
(3) The impurity protein with large molecular weight was removed by gel chromatography.