• Jun 20th 2007, 04:06 PM
labrat
1. If an instrument gives a reading "beyond linear limits" a dilution of a patients original serum sample is made and the test is rerun.The dilution is made by using 0.5ml of the serum and 2.0ml of water. The test is rerun, and the instrument now gives a result of 400mg/dl. What is the final result that is reported?

2.If 0.1ml of a patients serum is diluted with 0.4ml of water and the instrument gives a reading of 325 IU, what will be reported as the patient's result?
• Jun 20th 2007, 11:28 PM
CaptainBlack
Quote:

Originally Posted by labrat
1. If an instrument gives a reading "beyond linear limits" a dilution of a patients original serum sample is made and the test is rerun.The dilution is made by using 0.5ml of the serum and 2.0ml of water. The test is rerun, and the instrument now gives a result of 400mg/dl. What is the final result that is reported?

Diluting 0.5 ml with 2ml of water reduces the concentration of any solute by a factor or 0.5/(2+0.5) = 1/5.

So to recover the original concentration we multiply the instrument reading by 5.

Quote:

2.If 0.1ml of a patients serum is diluted with 0.4ml of water and the instrument gives a reading of 325 IU, what will be reported as the patient's result?
Same sort of thing here, the dilution factor is 0.1/(0.4+0.1)=1/5,
so multiply the instrument reading by 5 (assuming IU is a concentartion
of some kind).

RonL
• Jun 21st 2007, 07:07 AM
labrat
thank you very much
Thank you very much.:) I was having alot of trouble understanding the question. Very good explanation.