Final ProgramCPSA 2011
Science and Technology Coming Together to Make a Difference
October 3 - 6, 2011
Bucks County Sheraton Hotel
Langhorne, PA
Poster Abstract #04
Comparison of Microsampling Techniques for Quantitative DBS and DPS Preparation
1) Drummond Scientific Company; 2) University of Rochester
Purpose:
Recent studies concerning the possible impact of hematocrit and other matrix effects on dried blood spot (DBS) sampling points to the need for accurate and precise volume control for dried matrix spot (DMS) applications. A number of microsampling techniques can be used to transfer samples taken for spotting; however, most require significant user effort and few produce multiple spots. Here, we evaluate the precision of a prototype device that is easy to use and produces multiple spots from a single sample draw.
Methods:
Five - 15µl aliquots of whole sheep's blood were spotted onto Whatman FTA DMPK paper using Drummond's prototype DBS Incremental Dispenser with plugged microcapillary tubes. The precision of the aliquot volume dispensed was measured gravimetrically and compared to DBS samples prepared in a traditional manner (Drummond Microcaps with bulb dispenser). The Drummond prototype dispenser was also tested for precise spotting of 10µL plasma spots, using a novel self-sealing microhematocrit capillary tube.
Results:
Preliminary studies demonstrate that sample volume variations, based on SD and CV calculations, can be significant (CVs from 3.2% - 4.8%) and somewhat technique dependent when spotting with Microcaps, whereas Drummond's DBS Incremental Dispenser with plugged microcapillary tubes offers better consistency and control (CVs from 2.6% - 4.2%) over the range of aliquot volumes tested. Similar results (CVs from 2.4-2.9%) were also obtained for 10µL plasma spots, using Drummond's self-sealing plasma separating capillary tubes.
Conclusions:
The prototype Drummond's DBS and DPS dispensers introduced herein afford the ability to perform collection of blood sample, plasma separation (if necessary), and dispensing of multiple quantitative aliquots, all of a single tube. In addition to producing sample aliquots that are highly accurate and repeatable, the prototype dispensers do so in a manner that is both efficient(no time lost changing tips), cost effective(1 tube versus 3-5 tubes), and humane (reduces the number of draws taken from each animal). Further microsampling studies for quantitative DBS are soon to be completed, and evaluation of similar techniques for dried plasma spot (DPS) applications is planned.