Dilutions effectively reduce the overall concentration of an analyte by increasing the total volume of the solution. Instructions for performing a dilution vary significantly and sometimes cause confusion as to how much a volume of diluent needs to be added in order to create the needed dilution. One of the most common ways that laboratorians will see a request for a dilution is represented by the example below:
- Perform a "1 to 5" dilution. (This would have a dilution factor of 5.)
- This means for every 1 part of the original sample, there are 5 total parts of the final solution.
- Another way to interpret it is that for every 1 part of the original sample, there are 4 parts of diluent.
- 1 part of the original sample to 4 parts diluent is a ratio which sometimes is written as 1:4.
- "1 to 5" is NOT equivalent to "1:5" unless it states it is a 1:5 dilution. 1:5 dilution may be stated that way most commonly on serial dilutions which will be discussed soon.
- To perform a 1 to 5 dilution, 4 parts of diluent would be added to the 1 part of the original solution.
- DO NOT add 5 parts of diluent to 1 part of the original sample (that is a 1 to 6 dilution).
