To do this, .10 ml of a saline suspension of red blood cells labeled with 59over26 Fe is injected into the tail vein. Before injection the gamma rays were counted for this .10 mL solution and the count rate was found to be 1.0x10^-4 cpm. After a sufficient time for the blood to be thoroughly mixed, .10 ml of blood is removed and counted. the sample is found to have a count rate of 476 cpm. what is the approximate blood volume in mL in the mouse.
please provide explanation. im kind of confused on this problem
2007-02-25 08:19:17 · 1 answers · asked by galdon885 1 in Science & Mathematics ➔ Chemistry
OK. You inject the blood with your marker and you know the volume percentage of the marker in your sample.
After giving the blood sufficient time to mix with the rest of the blood, you draw the same sample size and get a concentration that is much lower. The ratio of first measure to second measure is the inverse of the ratio of blood volume to sample.
cr2 / cr1 = .10mL/ x
This is because the marker that was concentrated in the injected cells has diffused throughout the entire vascular system.
What I don't understand is why your second cr is HIGHER than your first one, but several orders of magnitude. Check the problem.
2007-02-25 08:32:59 · answer #1 · answered by TychaBrahe 7 · 0⤊ 0⤋