Conventional blood sampling techniques (such as through the vein), though effective, are highly invasive and require a skilled phlebotomist. With recent improvements in lab analysis, the amount of blood needed to accurately measure hormone levels has significantly reduced. This has led to an increased interest in microsampling techniques, such as VAMS (volumetric absorptive microsampling), in labs across the US.
The recent push for the adoption of microsampling allows samples to be collected from users in remote regions. Let’s dive into the pros and cons of each type of blood sampling techniques that are available today.
Conventional Intravenous Blood Sampling
Conventional blood sampling is the most common method for performing blood analysis. This method requires a phlebotomist to collect a relatively large volume of blood from your vein using a hypodermic needle connected to an evacuation tube. Once the sample is collected, it can be delivered to a laboratory for analysis.
- Since this is the dominant collection method globally, it’s not difficult to find a location that will perform this type of blood sampling for you.
- If performed correctly, this method will provide an accurate result.
- Skilled & trained phlebotomist required to perform the sample collection.
- Cannot/should not be done by yourself (at-home).
- Highly invasive technique. Many people are afraid of needles (affects about 1 in 10 people).
- High cost (due to the skilled labor needed).
- Overall a time-intensive process.
Dried Blood Spot (DBS) Filter Card Microsampling
An approach that attempts to bridge the gap between small blood sampling and analysis is dried blood spot (DBS). DBS was first developed in 1963. Dried blood spot (DBS) is the most common blood microsampling approach. It involves using a collection filter card to collect a sample of blood via finger-prick or heel-stick.
- Simple shipping requirements. Can be shipped using normal mail systems since the sample is stable for up to 2 weeks.
- Sample transportation can be performed at ambient temperature. Whole blood usually must be transferred refrigerated or frozen.
- Result accuracy is variable due to technical errors and biological fluctuations, such as hematocrit (HCT).
- When dropped a blood sample on the collection card, the HCT (thickness of your blood) affects the resulting size of a spot. A high HCT tends to give a smaller spot, and a low HCT yields a bigger spot. The HCT effect can introduce variation in analysis, such as the amount of analytes in the sample.
- Requires a drying period (up to 60 minutes) before the sample can be sealed and shipped.
Volumetric Absorptive Micro Sampling (VAMS)
Volumetric absorptive microsampling (VAMS) is a novel approach that allows the user to collect a fixed volume of blood. The technique involves the use of a collection device with a porous hydrophilic tip (resembles a Q-tip, but instead of a cotton swab on the end, there is a sponge). The special tip enables the collection of small, accurate, and precise blood volumes. The collection process time is short (typically around 3 seconds), regardless of the HCT level.
- Zero drying time required.
- Cost-effective and simple design.
- Highly accurate results.
- Able to be performed by yourself, at-home, in under 15 minutes.
- Minimally invasive technique.