This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Medicine
You have performed a pleural tap in a patient with suspected TB. You will send the sample for all of the following studies except: 
Select and explain. 
A. Gene Xpe, B. ADA, C. LDH, D. Albumin
D: Albumin
Answer: D: Albumin 
Explanation: Ans: D. Albumin(Ref: Harrison 19/c p1715-1716)The most impoant diagnostic tests in pleural fluid specimen in a patient with suspected TB are GeneXpe (PCR) and ADA levels.Total protein levels and LDH levels are required to differentiate between transudative and exudative effusion according to Light's Criteria.So doing a pleural fluid albumin level separately will not be very useful.Total protein estimation should be done instead.