In the modern biomedical laboratory, reagent kits containing all the necessary ingredients are premixed and supplied ready-to-use including a fresh unopened bottle of sterile deionized water.
Example of a kit by Bio-Rad designed for real-time PCR of fecal bacteria, used, for example, to test food products for contamination.
Kits are available from biotech suppliers for virtually any step or procedure a lab technician might conceivably carry out. Typically the user has to supply only the unknown sample, maybe a few custom ingredients, and a laboratory with the necessary basic equipment and services.
Kits have been prepared by professionals under GMP conditions, tested and guaranteed including a positive control, they allow for lab protocols to be reliably reproduced in different labs, and most obviously they have simplified the process of carrying out the instructions provided. The instructions ensure that different users follow the same Standard Operating Procedure (SOP).
I have been able to take advantage of the simplicity and clearly outlined instructions to train scientists with little or no laboratory experience in biology or biotechnology to perform DNA analysis. For example, I have trained environmental scientists, ecologists, geologists, and law students to extract DNA, splice plasmids, transform E.coli, clone, and sequence, and analyze DNA from water and soil samples they collected in the field. With a kit and simple instructions, almost anyone with basic lab skills can carry out sophisticated procedures.
It simply was unnecessary for them to understand the intricacies of buffer composition, presence of cofactors, ionic strength, concentration of primers or probes, etc. One could learn to follow the instructions, operate basic lab equipment, and get the necessary results and proceed with their analysis.
Unfortunately fewer biomedical scientists using the kits have knowledge of the kit components, their roles, and their constitution. In most cases, technology has advanced to the point that significant progress is being made without the need for lab techs to make all the ingredients from scratch.
This is a good thing in that reproducibility and standardization have improved. But what about the art of making the individual components that go into a pre-mixed kit? This skill will be retained by those who produce the kits, and individuals gifted with the abilities to constitute the buffers, enzymes, cofactors, stabilizers, and other ingredients will be in higher demand.
Will your favorite kits become trade secrets, and the exact chemical composition and mechanism of action kept confidential from the enquiring professional or researcher?
My experience with college students in chemistry and biology makes me somewhat concerned about this lack of basic and fundamental knowledge. Just like it isn't necessary to be an expert in microelectronics to use a cell phone, it isn't necessary for every lab tech to know all the minutia of an immunoassay.
However when my nurse--or doctor--or pharmacist--has to compound or reconstitute a potentially dangerous drug the stakes are more personal: I want to know that they graduated with a clear understanding of moles, molecular weight, molarity, percentage (%w or %v?), and a clear concept of the meticulous kinetics and thermodynamic principles that seemed so irrelevant and intellectual back then as a pre-professional undergraduate!