C.M. Isotope Query

// WP_Query arguments
$args = array (
	'post_type'              => array( 'post' ),
	'cat'                    => '3',
	'posts_per_page'         => '-1',
);

// The Query
$isotope_query = new WP_Query( $args );

// The Loop
if ( $isotope_query->have_posts() ) {
	while ( $isotope_query->have_posts() ) {
		$isotope_query->the_post();
		// do something
	}
} else {
	// no posts found
}

// Restore original Post Data
wp_reset_postdata();