Cytogenetic studies in spontaneous abortion: the Calgary experience.

In a series of 493 apparently consecutive products of spontaneous abortions obtained for cytogenetic studies, tissue culture was attempted in 428 cases; chromosome analysis using the Q-banding technique was completed in 215 cases (50.2%). Abnormal karyotypes were identified in 80 cases (37.

Additional evidence for fragile X activity in heterozygous carriers.

The result of a previous study showing an association between mental development and fragile X activity in heterozygous females is given further support by similar investigations of three additional kindreds. The increased frequency of demonstrable fragile X chromosomes in mentally retarded females appears to be due to an increase in the active fragile X while the inactive marker X remains at a similar low frequency in all heterozygotes whether retarded or not. The frequencies of the active fragile X separated the normal and abnormal subjects into two distinct populations.

Preparation of high resolution chromosomes from amniotic fluid cells.

A relatively simple method of obtaining high resolution chromosomes from amniotic fluid cells is described. The elongated chromosomes are achieved by adding ethidium bromide (5 micrograms/ml) to the culture 4 1/2 hours before harvesting and the high resolution banding can be produced by usual banding procedures.

Adaptation of human long-term B lymphoblastoid cell lines to chemically defined, serum-free media.

Attempts were made to adapt human long-term B lymphoblastoid cell lines to prolonged growth in serum-free, chemically defined media. A newly described medium, which is an enriched modification of Dulbecco's modified Eagle's medium containing additional amino acids and vitamins, was used. The serum is totally replaced by albumin, transferrin, and soybean lipid.

Porcine (Sus scrofa domestica) chromosome identification and suggested nomenclature.

Various banding techniques have been used for chromosome analysis in domestic pigs (Sus scrofa domestica). The techniques used in karyotype analysis were Q-banding by (CMA)2S, trypsin-G-banding, BrdU-Acridine-Orange R-Banding and C-banding. Sequential staining techniques of quinacrine-Giemsa were used to record the length of each chromosome and determine arm ratios.