PT - JOURNAL ARTICLE AU - R. E. Blewitt TI - A new method for the assay of factor XI in plasma and the preparation and use of a new artificial substrate AID - 10.1136/jcp.28.4.332 DP - 1975 Apr 01 TA - Journal of Clinical Pathology PG - 332--336 VI - 28 IP - 4 4099 - http://jcp.bmj.com/content/28/4/332.short 4100 - http://jcp.bmj.com/content/28/4/332.full SO - J Clin Pathol1975 Apr 01; 28 AB - An improved method for the one-stage assay of factor XI in plasma has been proposed; it is reproducible and compares well with an old, established method. A short investigation into the preparation and use of artificially prepared factor XI-deficient plasma has been carried out: this substrate can be used as an alternative to the congenitally deficient substrate.