Technical Information

Microspheres having a diameter of 15 µm are standard for the measurement of blood flow (1).  However, BioPAL's stable-isotope labeled microspheres can be provided in a range of different sizes.  For example, large microspheres (50 and 100 µm) can be used to induce an ischemic embolism (2,3), while smaller microspheres are used in a variety of particle deposition studies (4,5).  By labeling the microsphere, BioPAL can provide a quantitative measure of microsphere content.

BioPAL's assay procedure is not chemically or physically destructive and the measurement can be repeated (6).  Therefore, samples may be returned to the researcher for other analysis or archived for future reference.  The ability to re-assay stored samples is a major advantage for pharmaceutical development.

References

1. Circ Res 21,163 (1967)
2. Jpn J Pharmacol 78, 31 (1998)
3. Br J Pharmacol 121, 477 (1997)
4. Exp Lung Res 25, 495 (1999)
5. Lung 177, 289 (1999)
6. Anal Chim Acta 165, 1 (1984)

The Product

1. Customized Microspheres
   A range of microsphere sizes (1, 5, 10, 15, 20, 25, 30, 40, 100, 250, 600 µm) and labels are offered and can be customized to meet specific applications.  The microspheres are suspended in deionized water containing Tween 80 and 0.01% Thimerosal or can be provided as a dry powder.  Our stock at any given time will vary, therefore researcher are encouraged to call for availability.
2. Contaminant-Free, Sample Vials
   BioPAL's polypropylene sample vials are cleaned to remove trace contamination and are calibrated for our activation and counting system.  These vials must be used for the assay.
3. Assay Service
   BioPAL charges a per-sample assay fee.  The results of the assay are reported as the total disintegrations per minute (dpm) measured in each sample for each corresponding microsphere label.