discussion for serial dilution experiment

Either convention works fine as long as it is clear to everyone in the lab what dilution they are actually performing and being asked to perform. However, perhaps the majority of medical laboratory scientists are taught the ratio. Are they doing a true 1/10 (1 mL sample plus 9 mL diluent) or are they actually doing a 1 to 11 dilution (1 mL sample plus 10 mL diluent)? Your patient results may be different depending on who does the dilution!Ĭoming into this field from a scientific background rather than an MLS background, I prefer the convention of writing a dilution as 1 over something, ½, 1/10, rather than as a ratio, 1:2, 1:10. It’s very important to know how the technologists in the lab are performing that 1 to 10 dilution. I’ve seen 1 to 10 dilutions written both as 1/10 and 1:10. Unfortunately, this problem is prevalent in the laboratory. That will be 1 mL added to 2 mL, for a total of 3 mL, or a 1/3 dilution. In the scientific literature, if you see “1:2”, it means to add 1part to 2 parts. One is a dilution and the other is a ratio.

These two forms are actually not equal, despite the fact that they are used interchangeably in the laboratory. But many times it will be written as 1:2. That’s because I’ve found that the convention for writing dilutions is taught differently at different Medical Laboratory Science (MLS) schools.Ī 1 to 2 dilution should be written as ½. But if you ask people to do a 1 to 2 dilution, you may be surprised to get different results. If you ask someone to dilute a sample in half, pretty much everyone will do it the same way – add an equal volume of sample to an equal volume of diluent, whether that’s 1 mL to 1 mL or 100 µL to 100 µL.

Discussion for serial dilution experiment