Restriction fragment length polymorphism (RFLP) analysis was the first genetic test developed and is still used as of 2020, although it is being phased out by newer methods. It involves dicing the DNA with restriction enzymes and sorting the resulting restriction fragments by size using southern blot. The restriction enzymes EcoRI and BlnI are commonly used. EcoRI isolates the 4q and 10q repeat arrays, and BlnI dices the 10q sequence into small pieces, allowing 4q to be distinguished. The EcoRI restriction fragment is composed of three parts: 1) 5.7 kb proximal part, 2) the central, variable size D4Z4 repeat array, and 3) the distal part, usually 1.25 kb. The proximal portion has a sequence of DNA stainable by the probe p13E-11, which is commonly used to visualize the EcoRI fragment during southern blot. The name "p13E-11" reflects that it is a subclone of a DNA sequence designated as cosmid 13E during the human genome project. Considering that each D4Z4 repeat is 3.3 kb, and the EcoRI fragment contains 6.9 kb of DNA that is not part of the D4Z4 repeat array, the number of D4Z4 units can be calculated. D4Z4 repeats = (EcoRI length - 6.9) / 3.3Sometimes 4q or 10q will have a combination of D4Z4 and D4Z4-like repeats due to DNA exchange between 4q and 10q, which can yield erroneous results, requiring more detailed workup. Sometimes D4Z4 repeat array deletions can include the p13E-11 binding site, warranting use of alternate probes.
Triprolidine is an over-the-counter antihistamine with anticholinergic properties. It is used to combat the symptoms associated with allergies and is sometimes combined with other cold medications designed to provide general relief for flu-like symptoms. As with many antihistamines, the most common side effect is drowsiness.It was patented in 1948 and came into medical use in 1953. See also
Benztropine
Pseudoephedrine
UK-9040


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