I think ELISA methods are sensitive enough to measure T3/T4 in any tissue these days.......plus RIA...is probably a pain to set up. Almost all labs for routine testing use ELISA or chemiluminescence for measurement.

Absolutely u can use LC-MS...but u have to do cleanup of your sample....There are various SPE methods. Since u r only interested in T3/T4...its a piece of cake.

Thank you Dimitris. I am planning to use LC-MS/MS analysis for measuring T3 and T4 levels in adipose tissue. 

 I want to share my procedure to prepare the adipose tissue sample. In brief,

1. Adipose tissue will be homogenized in a buffer containing 10mM HEPES, 0.25 M sucrose, 1 mM EDTA, DTT, ascorbic acid and protease inhibitor cocktail (pH7.5). 

2. The homogenate will be centrifuged at 1000 g at 4°C  for 25 minutes. The infranatant (liquid between the fat cake and pellet) will be collected carefully. 

3. 1ml of acetone will be added to the infranatant  and will be allowed to sit for 30 mins. Then the solution will be vortexed and it will be centrifuged at 1,600g for 5 mins at 25°C. 

4. After acetone extraction, the sample will be run through solid phase extraction in C18 SAP-PK column prequilibriated with 60% acetone, 39% water and 1% trifluoroacetic acid. 

Then we will perform the usual elution and other steps as described in published papers. Am I doing everything correctly? Please give me your valuable suggestion.

Thanks.

Hi, Afsana! The prosedure to my mind is correct. What is the retio of acetone : infranatant? Do you have any problem with the analysis? What is the recovery of the analytes?

Concerning ELISA the problen is not a sensitivity but a selectivity and as a result false positive results.