?
Solved

Help us with a laboratory protocol

Posted on 2011-05-04
12
Medium Priority
?
289 Views
Last Modified: 2012-05-11
We process geologic samples in a mass spectrometer. There is a flaw in the protocol. Help us figure out a better way. Here's what we do:

1. Put small amount (measured in micrograms) of a sample into silver capsule. The silver capsule is a cylinder with one open end. It is very small, 2mm in diameter. After the sample is put in the capsule, the capsule is pinched shut and the top folded over twice.

2. Put capsule in the assay tray. Record on paper the position of the capsule. E.g. Cell A1 has sample from Site X. There are not identifying marks on the capsule itself.

3. The tray is 8 x 12, so as many as 96 samples might go in. Repeat 1 and 2 as needed.

4. Take tray to mass spectrometer. Put about 10-15 samples in mass spectrometer, leave the rest of samples in tray until the 10-15 are run.

The problem happens between steps 3 and 4. A couple of times, the tray has been knocked, causing the capsules to fall out. When this happens the information about which capsule contained a sample from which site it lost. For example, we don't know which capsule was in A1.

One thought was to stamp the capsule with the cell #, e.g. A1, before loading the sample, but this would not work because it would not be possible to undo the folding of the capsule to see the stamp. This also assumes we could get really small stamps.
0
Comment
Question by:allelopath
  • 4
  • 2
  • 2
  • +3
12 Comments
 
LVL 17
ID: 35694625
Can you use ink to identify the capsules? If this won't contaminate your readings you could use bands or dots of colour like an electrical resistor colour code to number the capsules.

If this won't work then perhaps using smaller containers, just to hold enough samples for one spectrometer test so the rest can remain covered and can't get knocked. At most you would mix up 10-15 samples then so it should be an improvement.
0
 
LVL 27

Expert Comment

by:aburr
ID: 35694953
Engrave the bottom of the silver with a small number. Use small engraving tool. The number will be hard to read but hopefully you will not have to read them often
0
 
LVL 1

Author Comment

by:allelopath
ID: 35695383
Thanks for the replies.

Unfortunately I think these won't work. To use colors, we need 96 colors, and someone able to distinguish them. Engraving on the bottom would require the skills of a surgeon.

0
Technology Partners: We Want Your Opinion!

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

 
LVL 26

Expert Comment

by:Nick67
ID: 35695471
96 colors?
Why?
12 colors.
That's how transistors and resistors get done.
Each color that's not black or white represents a digit
White represents the beginning, black the end.
Each digit is represented by a color.
12 colors can thus represent an unlimited number--if you have the space.
2 mm in diameter -- but how long?
0
 
LVL 37

Assisted Solution

by:TommySzalapski
TommySzalapski earned 800 total points
ID: 35697934
No offense, but it's terrible practice to have samples unlabled for any length of time at all. The resistor code idea is a good one. One color per digit and one to signify start (don't see why you'd need an end color). The mapping they use for resistors is fairly intuitive http://wiki.xtronics.com/index.php/Resistor_Codes so it might be good to actually use those.

The other option would be to simply put each silver capsule into a larger container and label that. You could get small plastic tubes with blank labels already on them.
0
 
LVL 27

Expert Comment

by:d-glitch
ID: 35698513
Is there any reason the box can't have a tight cover when it is in motion.

Or a dab of a compatible adhesive to keep each sample in place?
0
 
LVL 1

Author Comment

by:allelopath
ID: 35698662
>it's terrible practice to have samples unlabled for any length of time at all
I know. That's why we're trying to fix it.
0
 
LVL 1

Author Comment

by:allelopath
ID: 35698732
I need to ask the mass spec guy if coloring the capsules will affect the results.

The cover is a good idea. Though there would still be some time when the capsules could be knocked out, a cover limits that time.

Adhesive: another idea I hadn't considered ... it have to be weak enough to be able to get the capsule back out. Any adhesive on the capsule may affect results, as well. Not sure.
0
 
LVL 26

Expert Comment

by:Nick67
ID: 35699043
What about weak adhesive a la post-it notes on the tray?
The adhesive would stay on the tray, and the capsules would cling to it?
0
 
LVL 27

Accepted Solution

by:
d-glitch earned 1200 total points
ID: 35699171
There are pill boxes with 7 and 28 and maybe more compartments.

Procedurally you could require that there never be more than one
compartment open.

     http://www.amazon.com/Apothecary-Products-Pill-Dispenser-Month/dp/B00078ZJQA/ref=pd_sim_hpc_1
0
 
LVL 1

Author Comment

by:allelopath
ID: 35703509
d-glitch: The pill boxes are the best idea presented here.
TommyS*: The tube idea is also a good one.

Any substance such as ink, paint, or glue will not work because it will affect the results. The capsules are even handled with tweezers so as not to get oil from skin on them.
0
 
LVL 37

Expert Comment

by:TommySzalapski
ID: 35705757
In that case you certainly shouldn't have them touching each other. Ever. Glad you got a solution.
0

Featured Post

Hire Technology Freelancers with Gigs

Work with freelancers specializing in everything from database administration to programming, who have proven themselves as experts in their field. Hire the best, collaborate easily, pay securely, and get projects done right.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Gift cards are not a new concept - it's been around for a very long time.  Undoubtedly, over the past you have received such a card or purchased one for a friend or relative.  Are you aware that you've been feeding the machine?  If not, read on :)
This article provides a brief introduction to tissue engineering, the process by which organs can be grown artificially. It covers the problems with organ transplants, the tissue engineering process, and the current successes and problems of the tec…
The viewer will learn how to use NetBeans IDE 8.0 for Windows to connect to a MySQL database. Open Services Panel: Create a new connection using New Connection Wizard: Create a test database called eetutorial: Create a new test tabel called ee…
THe viewer will learn how to use NetBeans IDE 8.0 for Windows to perform CRUD operations on a MySql database.
Suggested Courses

750 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question