[Tex/LaTex] How to make figure caption boldface

Question

When I create a figure caption, LaTeX automatically creates the Figure1: part and then the caption. How to make the Figure1 part boldface? My figure TeX codes is this:

\begin{figure}[ht!]
\includegraphics[width=80mm]{images/tftype.png}|\includegraphics[width=80mm]{images/tftype1.png}
\caption{An overview of structural variants of transcription factors. Each specific variant binds to a certain class of DNA motifs (shown in blue).  Some of the motifs have a high affinity for the TATAAA box were others favor specific sequences somewhere in the promoter region. {\small http://www.nature.com/scitable/resource?action=showFullImageForTopic\&imgSrc=37950/sadava\_14\_15\_FULL.gif}}
\end{figure}

I'm a beginning TeX user and some things are still strange to me. Any help is appreciated.

My desired output is : Figure1: some very interesting information

Answer 1

You can use the caption package; the labelfont key allows you to specify bf:

\documentclass{article}
\usepackage{caption}
\captionsetup[figure]{labelfont=bf}

\begin{document}

\begin{figure}
\centering
A
\caption{test figure}
\end{figure}

\end{document}

If this is to apply to all floats (not just figure), instead of

\captionsetup[figure]{labelfont=bf}

load the package in the following way:

\usepackage[labelfont=bf]{caption}