The phrase "a was then" is not correct and does not make sense in written English.
It appears to be a fragment and lacks clarity or context for proper usage.
Example: "There was then a moment of silence before the announcement."
Alternatives: "there was at that time" or "there existed then".
gDNA extracted with the standard phenol⁄chloroform method and treated with RNase A was then precipitated with 5.2 M ammonium acetate and dissolved in 20 30 μl HPLC water.
The derived sequence pattern RRTWRBVYRYRYTDYY (IUPAC nomenclature where R is purine, Y is pyrimidine W is A or T, V is not T, D is not C and B is not A) was then used to search the human promoter database.
The ethidium bromide-stained PFGE gel (fig. 1 A) was then subjected to Southern-blot analysis (fig. 1 B).
The initial condition (100%% eluent A) was then restored in 1 min and maintained for 9 min to recondition the column.
Subsequently, this liquid was also transferred to Tube A. The protein-containing solution in Tube A was then dried completely via speed vacuum.
For clarity, "clade A" was then named Stevardiinae and, as presently recognized, is widely distributed in the Neotropics on both sides of the Andes, from Costa Rica in Central America to central Argentina.
The mutant A is then introduced at low frequency.
SP-A was then treated with polymyxin agarose beads to remove endotoxin as previously described [12].
Another bilingual translator who blinded to the FS-A was then asked to complete the back-translation.
Primary antibody against p-STAT1 (1 : 300 dilution) in solution-A was then added and incubated for 2 h at 37 °C.
FLAG-tagged Aurora-A and HA-tagged ubiquitin were transfected to 293T cells with or without CUL3 and KLHL18, ubiquitylated Aurora-A was then immunoprecipitated by anti-FLAG antibody, and detected by anti-HA antibody.
