% Minimal skeleton: columnset + columnsetspans + the qPCR table only.
% All fonts, colours, interaction, heads, captions styles and other setup removed.
% Body prose replaced with ConTeXt sample text.

% --- table rules kept (head rule + bottom rule) and float placement ---
\setupfloat[table][default={here,tblr,nonumber}]
\setupxtable[frame=off]
\setupxtable[head][topframe=on,bodyfont=bf]
\setupxtable[lastrow][bottomframe=on]

% --- the bits you asked to keep ---
\definecolumnset[main][n=2,balance=yes,distance=10mm]
\definecolumnsetspan[wide][n=2]

\starttext
\startcolumnset[main]

\startcolumnsetspan[wide]
\samplefile{ward}
\stopcolumnsetspan

\samplefile{knuth}

\samplefile{tufte}

\startcolumnsetspan[wide]

\startplacetable[title={Table 1 \emdash{} Lorem ipsum dolor sit amet consectetur.}]
\startxtable
\startxtablehead[head]
\startxrowgroup[lastrow]
\startxrow
\startxcell[align=right] Stage \stopxcell
\startxcell[align=right] Step \stopxcell
\startxcell[align=right] Temperature~/~°C \stopxcell
\startxcell[align=right] Time~/~minutes \stopxcell
\startxcell[align=right] Number of Cycles \stopxcell
\stopxrow
\stopxrowgroup
\stopxtablehead
\startxtablebody[body]
\startxrow
\startxcell[align=right] Holding \stopxcell
\startxcell[align=right] UDG Activation \stopxcell
\startxcell[align=right] 50 \stopxcell
\startxcell[align=right] 2 \stopxcell
\startxcell[align=right] 1 \stopxcell
\stopxrow
\startxrow
\startxcell[align=right] Holding \stopxcell
\startxcell[align=right] Dual-Lock DNA Polymerase Activation \stopxcell
\startxcell[align=right] 95 \stopxcell
\startxcell[align=right] 10 \stopxcell
\startxcell[align=right] 1 \stopxcell
\stopxrow
\startxrow
\startxcell[align=right,nr=2] PCR Cycling \stopxcell
\startxcell[align=right] Denaturation \stopxcell
\startxcell[align=right] 95 \stopxcell
\startxcell[align=right] 0.25 \stopxcell
\startxcell[align=right,nr=2] 35 \stopxcell
\stopxrow
\startxrow
\startxcell[align=right] Annealing \stopxcell
\startxcell[align=right] 60 \stopxcell
\startxcell[align=right] 0.75 \stopxcell
\stopxrow
\startxrow
\startxcell[align=right,nr=3] Melt Curve (Continuous) \stopxcell
\startxcell[align=right] Denaturation \stopxcell
\startxcell[align=right] 95 \stopxcell
\startxcell[align=right] 0.25 \stopxcell
\startxcell[align=right,nr=3] 1 \stopxcell
\stopxrow
\startxrow
\startxcell[align=right] Annealing \stopxcell
\startxcell[align=right] 60 \stopxcell
\startxcell[align=right] 1 \stopxcell
\stopxrow
\startxrowgroup[lastrow]
\startxrow
\startxcell[align=right] Denaturation \stopxcell
\startxcell[align=right] 95 \stopxcell
\startxcell[align=right] Continuous \stopxcell
\stopxrow
\stopxrowgroup
\stopxtablebody
\startxtablefoot[foot]
\stopxtablefoot
\stopxtable
\stopplacetable

\stopcolumnsetspan

\samplefile{douglas}

\stopcolumnset
\stoptext