Measurement of Total, Ultrafilterable and Ionised Serum Calcium

The development and assessment of methods for measurement of total, ultrafilterable and ionised serum calcium is given. An existing fluorimetric technique for total calcium has been automated and modified for routine use. A device for rapidly preparing serum ultrafiltrates has been developed and an electrometric method for ionised calcium measurement assessed. Values in normal subjects are given for all three fractions and compared with the findings of other workers.