venipuncture alternatives: 4 methods to consider
The venipuncture sampling method remains the norm for sampling in most instances, though alternatives to venipuncture are becoming more popular for many reasons.
The development of sophisticated biometrics and analytic equipment has led to a trend toward significantly smaller volume blood samples and eliminating the need for special handling and refrigeration. Standard blood draws are usually taken from the medial cubital vein of the arm on the anterior side of the elbow. This vein is relatively accessible and close to the skin.
Typical whole venipuncture blood sample volumes vary according to weight and frequency, but 100ml is the usual one-time draw for a person weighing approximately 100 lbs.
Alternatives to Venipuncture Sampling
Four less invasive options have become available. Each requires a substantially smaller sample size for accurate analysis. Important breakthroughs have resulted from developments in sample taking devices and more sophisticated analytical capability.
1. Dried Blood Spots (DBS)
Old-fashioned DBS cards were first used in the 1960s for newborns whose total blood volume was too small for regular blood sampling. The method was a lifesaver and continues to have value for adults as well. The drop-sized sample, placed on a specially treated card and dried, can be transported without any special handling. This pioneering version of microsampling can be performed from a remote location.
2. Pre-Cut Dried Blood Spot (PCDBS)
This method requires a specific volume of blood to minimize the discrepancies that exist with the standard DBS samples. While the PCDBS method is as effective as other microsampling methods, the fixed quantity of the sample requires the sampling can only be performed by a trained technician.
3. Dried Plasma Spot (DPS)
Plasma sampling is used only when whole blood analysis is not required. The finger-prick sample can be self-administered. The process relies on an ingeniously designed, multi-layered collection card. Once the blood droplet is placed on the collection card, the patient or technician peels away a top layer after a measured time period. Meanwhile, a plasma spot has formed that is dried and sent off to the laboratory without special treatment.
VAMS sampling is self-administered using Mitra® collection devices. The technique requires a single finger-prick droplet of blood, 10-20µL worth, that is sealed in the VAMS device and sent to the lab.