The phrase "a first population of" is correct and usable in written English.
It can be used when referring to an initial group or set of individuals within a larger context, often in scientific or demographic discussions.
Example: "In our study, we observed a first population of migratory birds that arrived earlier than expected."
Alternatives: "an initial group of" or "a primary set of".
A five-CV linear gradient up to 35% SP-elution buffer separated impurities from a first population of ComFB, which began eluting at 35% of elution buffer.
We now consider the more complicated case where protein is initially at equilibrium with a first population of liposomes (total lipid concentration [ L]/2) and a second population of liposomes is introduced at time t=0 (also with total lipid concentration [ L]/2).
This also include CNP from BAC microarray analysis in a first population of 55 individuals (Iafrate et al., 2004), a second population of 47 individuals (Sharp et al., 2005) as well as in the HapMap Phase II data (Redon et al., 2006).
A second population of around 400 mountain gorillas live in Uganda's Bwindi Impenetrable national park.
"If we tackle the issues that currently prevent them from establishing naturally on Floreana, we could expect a third population of mockingbirds within five years," said Ortiz Catedral.
We consider two populations of excitatory neurons, each with extensive recurrent circuitry, and a third population of inhibitory neurons.
Furthermore, the presence of a second population of voids was concluded to strongly affect the fracture strain of the high strength regions of the welds.
Another extraordinary chapter in the saga was written last year, when a second population of the big ugly fish turned up some 10,000 kilometers away in Indonesia.
Application of transverse stretching to these films possessing semicrystalline structure gradually destroys the crystalline structure oriented in MD during this realignment while establishing a second population of oriented but poorly ordered crystallites in TD.
Offshore: A third population of killer whales in the northeast Pacific was discovered in 1988, when a humpback whale researcher observed them in open water.
