The Pi System: Its Study by means of Thin-Layer-Gel Electrofocusing in Polyacrylamide Gel

Pi phenotypes of alpha1‐antitrypsin in Southern England: Identification of M subtypes and implications for genetic studies

“…Assignment of Pi phenotypes was made using three separate isoelectric focusing techniques. The first method employed thin-layer polyacrylamide gel isoelectrofocusing in a p H gradient of 3.5-5.5 as 0009-9163/79/050406-05$02.50/0 0 1979 Munksgaard, Copenhagen previously described (Arnaud et al 1975). The second focusing method involved the use of 0.5-470 polyethylene glycol (PEG, mol.…”

Alpha‐I‐antitrypsin (Pi) phenotypes in Lyon, France: departure from Hardy‐Weinberg equilibrium

“…The subjects were all white Caucasians between 18 and 56 years of age. Pi determinations were made by isoelectric focusing in thin-layer polyacrylamide gels at pH 4-6, as described previously (Arnaud et al 1975). In order to test the validity of the equilibrium, the gene frequencies were calculated from the sample populations, and then from those frequencies the expected frequencies for the various phenotypes were computed.…”

Pi (Antitrypsin) Typing Methods

“…All definite isoelectric Pi typing runs were conducted using the LKB Mulliphor apparatus (LKB-Produkter AB, Bromma, Swden): the Sheffield laboratory used 2-mm gels [1] and the Bois Guillaume laboratory used 1-mm gels [7], Each sample was tested only once unless discrepancies were found after the coding had been broken.…”

“…Fur thermore, the AACE requires relatively large quantities of antiserum against human eq-antitrypsin, which makes the traditional typing system expensive. The recent introduction of isoelectric focusing (IEF) with a pH gradient of 4-6 [1,7] has produced a technique which could allow more laboratories to perform Pi typing. The aim of this study was to compare the Pi typing results in a series of samples obtained in three reference laboratories, one using ASGE and AACE and two using the IEF technique.…”