Hello i hope everyone is having a great time at SIP now. its been so long now. For today i'll be blogging on osmolality. and my lab uses a different equipment from our school's. it seems to be more advanced. well on to it =)

Osmolality is an expression of total concentration of dissolved particles in a solute without regard to the particle size, density or electrical charge. The measure of total solute concentration can only be made indirectly by comparing one of the solution colligative properties with corresponding cardinal property of pure solvent.
Vapro osmometer is based upon a measurement of vapor pressure depression made possible by thermocouple hygrometry. This sensitive temperature sensor operates on the basis of a thermal energy balancing principle to measure the dew point temperature within the chamber.
10 micro liter of specimen is aspirated into a micropipette tip and then inoculated into a solute free paper disc. The paper disc is then pushed into the instrument and sample chamber is locked. The sensing element is a fine wire thermocouple hygrometer. This is suspended in a unique, all metal mount, which forms a small chamber enclosing the specimen when joined with the sample holderAs vapor pressure equilibrates in the chamber airspace, the thermocouple then seeks the dew point temperature within the enclosed space, giving an output proportional to the differential temperature. The difference between ambient temperature and dew point temperature is the dew point depressionSample used- serum or urineStepwise.push sample chamber level upwards and pull the sample slide out from the instrument.
use forceps supplied to place a single sample disc in the central depression of the sample holder. If more than two discs are used, results will slightly elevated

Using a micropipette, pipette 10ul of sample

Rest pipette tip on the notch of pipettor guide. It should be about 5mm away from center of sample discsmoothly depress micropipette plunger to release sample onto sample discwith plunger still held down, lightly touch the pipette tip to sample disc, then lift it away. Tip must briefly contact sample disc to press the disc flat against the holder

Sample disc should appear fully saturated, with a slight liquid meniscus on surface.

Note: when cleaning the sample chamber, use only lint free tissue. Facial or soft tissue will produce excessive lint residue that will contaminate the thermocouple sensor

Yuxuan