Why did you switch to red-top tubes for progesterone and oestradiol finger-prick tests?
Based on our partner laboratory's findings, red-top tubes provide more accurate results for progesterone finger-prick tests when your progesterone levels are very high and oestradiol finger-prick tests at any oestradiol level. The change ensures that our tests are as precise and reliable as possible.
What happens to oestradiol and progesterone samples collected with a yellow-top finger-prick tube?
The gel inside yellow-top finger-prick tubes can affect the concentration of oestradiol and progesterone in the sample, occasionally causing lower-than-expected results. The gel’s surface area is relatively large compared to the small volume of blood and it’s thought that the gel can absorb some of the hormone from the sample. Note that this is only known to affect oestradiol and progesterone.
Are venous samples with yellow-top tubes affected in the same way as finger-prick samples?
No, our new laboratory's tests have shown that the results from yellow-top venous tubes remain consistent and unaffected.
I've used a yellow-top tube for oestradiol or progesterone tests before. Should I be concerned?
Rest assured, any tests you took previously are still valid, and the interpretation of your results is very unlikely to be different.