The phrase "a second sample was" is correct and usable in written English.
It can be used when referring to the collection or analysis of a second sample in a study or experiment.
Example: "After analyzing the first sample, a second sample was collected to ensure the accuracy of the results."
Alternatives: "another sample was" or "a subsequent sample was".
A second sample was obtained with a sampling device and suspended in 20 ml of the PreservCyt Solution (Cytyc/Hologic, Marlborough, MA, USA) for H-HPV DNA testing.
He also tested positive when a second sample was taken on the night of his fight against Hunt.
For patients with negative direct smear, a second sample was split, with SOC (raw sputum) and OM-S portions (sediment) tested in the Xpert MTB/RIF (Xpert) assay.
To identify genes involved in RA susceptibility, we investigated the association between putative functional single-nucleotide polymorphisms (SNPs) and RA among white individuals by use of a case-control study design; a second sample was tested for replication.
A second sample was obtained after mechanical debridement, decontamination of the implant surface with the test or control substance, and subsequent rinsing with sterile saline (Tpost).
A parallel experiment was conducted for phenotypic evaluation as described above with the exception that a second sample was taken 85 DAS from plants grown in 50-l pots.
When the results of the three diagnostic methods were negative and the clinical picture deteriorated even when antibiotic therapy was given, a second sample was taken to discard a fungal keratitis (patients 9 and 14).
A second sample was presented, this time a fragment of a real recording, and the subject was told that this example is such that it would receive the highest ratings in terms of audio quality.
In the cases of patients 9 and 15, a second sample was taken to corroborate the first PCR results due to the fact that they did not show a typical clinical picture of fungal keratitis (patient 9 showed a crystalline keratopathy [9]), or the fungus identified was not a typical fungus found in keratitis (patient 15 showed a keratitis by Pyrenochaeta keratinophila, sp nova [10, 11]).
A second sample was taken at the time the index case successfully completed therapy.
A second sample was collected the following day before inclusion in the trial.
