Go Back  Bike Forums > Bike Forums > Road Cycling
Reload this Page >

Hey, science types (doping question) . . .

Notices
Road Cycling It is by riding a bicycle that you learn the contours of a country best, since you have to sweat up the hills and coast down them. Thus you remember them as they actually are, while in a motor car only a high hill impresses you, and you have no such accurate remembrance of country you have driven through as you gain by riding a bicycle. -- Ernest Hemingway

Hey, science types (doping question) . . .

Old 07-01-09, 09:34 AM
  #1  
I'm so much cooler online
Thread Starter
 
eriksbliss's Avatar
 
Join Date: Apr 2006
Location: San Diego
Posts: 297
Likes: 0
Liked 0 Times in 0 Posts
Hey, science types (doping question) . . .

"Silence-Lotto's Thomas Dekker will miss the Tour de France after testing positive for the banned blood-booster EPO, his team announced on Wednesday. The sample was originally taken on December 24, of 2007, when Dekker was a member of the Rabobank team. The sample was re-tested using new techniques, which resulted in a positive test for EPO."

Assuming that the sample was sealed, frozen, and untouched for two years, are there any inherent concerns with testing a two-year-old sample? Degradation, contamination, something?
eriksbliss is offline  
Old 07-01-09, 09:38 AM
  #2  
Senior Member
 
SteelCan's Avatar
 
Join Date: May 2009
Location: So. Jersey
Posts: 596

Bikes: LeMond Reno

Likes: 0
Liked 0 Times in 0 Posts
Sorry can't provide an answer but will also add concern about
chain of custody of that sample.
SteelCan is offline  
Old 07-01-09, 09:42 AM
  #3  
Senior Member
 
gabdy's Avatar
 
Join Date: May 2005
Posts: 1,485

Bikes: Trek, Giant, PoS

Likes: 0
Liked 0 Times in 0 Posts
__________________
Courage
Skill
gabdy is offline  
Old 07-01-09, 09:51 AM
  #4  
Bromptoneer
 
Join Date: Jun 2008
Location: Brooklyn, NY
Posts: 2,942

Bikes: Brompton S2L

Likes: 0
Liked 0 Times in 0 Posts
I'm not a biologist, but assuming it wasn't tampered with and stored properly, it should be fine and legit. But of course, that's a lot of assuming.
Tsuru is offline  
Old 07-01-09, 09:59 AM
  #5  
Senior Member
 
rankin116's Avatar
 
Join Date: Jun 2007
Location: ChapelBorro NC
Posts: 4,126
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by eriksbliss
"Silence-Lotto's Thomas Dekker will miss the Tour de France after testing positive for the banned blood-booster EPO, his team announced on Wednesday. The sample was originally taken on December 24, of 2007, when Dekker was a member of the Rabobank team. The sample was re-tested using new techniques, which resulted in a positive test for EPO."

Assuming that the sample was sealed, frozen, and untouched for two years, are there any inherent concerns with testing a two-year-old sample? Degradation, contamination, something?
Many concerns from my point of view. Proteins don't do freeze/thaw cycles well, but I don't know if a denatured Epo sample would be undetectable, or if something else in the sample could pop as a false positive. I also don't know if the sample went through any freeze/thaw cycles at all for that matter.

Originally Posted by Tsuru
I'm not a biologist, but assuming it wasn't tampered with and stored properly, it should be fine and legit. But of course, that's a lot of assuming.
What exactly is 'stored properly' though?
rankin116 is offline  
Old 07-01-09, 10:18 AM
  #6  
Member
 
Join Date: Mar 2008
Location: San Diego CA
Posts: 36
Likes: 0
Liked 0 Times in 0 Posts
As a general rule, if the sample has been well stored it is fine. We often will measure protein levels from blood that has been frozen for ten or more years.
whistler is offline  
Old 07-01-09, 11:07 PM
  #7  
Senior Member
 
grolby's Avatar
 
Join Date: Jan 2005
Location: BOSTON BABY
Posts: 9,789
Liked 86 Times in 60 Posts
Originally Posted by rankin116
Many concerns from my point of view. Proteins don't do freeze/thaw cycles well, but I don't know if a denatured Epo sample would be undetectable, or if something else in the sample could pop as a false positive. I also don't know if the sample went through any freeze/thaw cycles at all for that matter.
Meh. It's probably stored at -80 degrees. It was no doubt thawed for the first test. It probably gets moved from one -80 freezer to another and then back about once a year due to the need to defrost freezers every so often to keep them working right. Not enough time out of the freezer to thaw. As molecular biologist who needs to use this kind of equipment, I can tell you that we take this pretty seriously - stuff will not get lost. But there isn't a lot of paperwork involved in this kind of routine lab maintenance, either. Things aren't watched at all hours. This might not sound good, but the reality is that there's just not any serious threat of things being misplaced; we're good at keeping track of things. A big deal is made about the supposed sensitivity of biological samples by people who aren't in the field. The reality: it takes some pretty serious negligence to mess up a sample. It doesn't happen too often. My take is that the scientists are that last people I would worry about in this process.
grolby is offline  
Old 07-01-09, 11:21 PM
  #8  
Senior Member
 
daxr's Avatar
 
Join Date: Feb 2009
Location: K.F., Orygun
Posts: 905

Bikes: 08 Giant Boulder, 08 Scattante XLR

Likes: 0
Liked 1 Time in 1 Post
Originally Posted by eriksbliss
"Silence-Lotto's Thomas Dekker will miss the Tour de France after testing positive for the banned blood-booster EPO, his team announced on Wednesday. The sample was originally taken on December 24, of 2007, when Dekker was a member of the Rabobank team. The sample was re-tested using new techniques, which resulted in a positive test for EPO."

Assuming that the sample was sealed, frozen, and untouched for two years, are there any inherent concerns with testing a two-year-old sample? Degradation, contamination, something?
Worth mentioning - they only dug deep because of a history of questionable samples or borderline results for the guy, for which Rabobank had already let him go.
daxr is offline  
Old 07-01-09, 11:21 PM
  #9  
A Free Radical
 
ImRael's Avatar
 
Join Date: Mar 2009
Posts: 446
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by grolby
Meh. It's probably stored at -80 degrees. It was no doubt thawed for the first test. It probably gets moved from one -80 freezer to another and then back about once a year due to the need to defrost freezers every so often to keep them working right. Not enough time out of the freezer to thaw. As molecular biologist who needs to use this kind of equipment, I can tell you that we take this pretty seriously - stuff will not get lost. But there isn't a lot of paperwork involved in this kind of routine lab maintenance, either. Things aren't watched at all hours. This might not sound good, but the reality is that there's just not any serious threat of things being misplaced; we're good at keeping track of things. A big deal is made about the supposed sensitivity of biological samples by people who aren't in the field. The reality: it takes some pretty serious negligence to mess up a sample. It doesn't happen too often. My take is that the scientists are that last people I would worry about in this process.

But, is this stuff really stored/watched by molecular biologists or lab techs?
ImRael is offline  
Old 07-02-09, 08:18 AM
  #10  
Senior Member
 
Join Date: Feb 2007
Posts: 3,917
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by ImRael
But, is this stuff really stored/watched by molecular biologists or lab techs?
Yes... and under lock and key.
wfrogge is offline  
Old 07-02-09, 10:14 AM
  #11  
Senior Member
 
Ratfish's Avatar
 
Join Date: Apr 2007
Location: Mle Island
Posts: 1,016
Likes: 0
Liked 0 Times in 0 Posts
I think normal urine doesn't "degrade" to the point where synthetic EPO is present.
Ratfish is offline  
Old 07-02-09, 12:10 PM
  #12  
Senior Member
 
Stray8's Avatar
 
Join Date: Aug 2008
Location: Nueva York
Posts: 647
Likes: 0
Liked 1 Time in 1 Post
Exogenous EPO can often be detected in blood, due to slight difference from the endogenous protein, for example in features of posttranslational modification.
https://en.wikipedia.org/wiki/Erythropoietin


Which means that synthetically introduced erythropoietin (EPO) can be differentiated from naturally occurring body-produced erythropoietin through the use of mass spectrometry. The nature of this indication test pretty much eliminates the possibility of an aged sample degrading into any components which might cause a "false positive" (i.e. it's either present...or it isn't).

So as mentioned above, the chain of custody has to be demonstrably solid so that the possibility of someone intentionally sabotaging the sample by introducing synthetic EPO can be eliminated as a cause.

.

Last edited by Stray8; 07-02-09 at 12:33 PM.
Stray8 is offline  
Old 07-02-09, 12:40 PM
  #13  
Senior Member
 
Cateye's Avatar
 
Join Date: Aug 2007
Location: Lactate Threshold
Posts: 584

Bikes: Orbea

Likes: 0
Liked 0 Times in 0 Posts
The chain of custody would worry me. You give a sample and two years later they find something? For two years you had no positive control over your own sample and have to trust someone else? Not a very good system.


Cateye is offline  

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Your Privacy Choices -

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.