The reaction that the luminol and hydrogen peroxide creates doesn't last long at all -- maybe a couple of minutes.
1	The	the	DET	DT	Definite=Def|PronType=Art	2	det	2:det	Discourse=elaboration-additional:94->93:0|Entity=(103-event-new-cf3-2-sgl
2	reaction	reaction	NOUN	NN	Number=Sing	12	nsubj	9:obj|12:nsubj	_
3	that	that	PRON	WDT	PronType=Rel	9	obj	2:ref	Discourse=elaboration-attribute:95->94:0
4	the	the	DET	DT	Definite=Def|PronType=Art	5	det	5:det	Entity=(18-substance-giv:inact-cf1-2-coref-Luminol
5	luminol	luminol	NOUN	NN	Number=Sing	9	nsubj	9:nsubj	Entity=18)
6	and	and	CCONJ	CC	_	8	cc	8:cc	_
7	hydrogen	hydrogen	NOUN	NN	Number=Sing	8	compound	8:compound	Entity=(4-substance-giv:inact-cf2-2-coref
8	peroxide	peroxide	NOUN	NN	Number=Sing	5	conj	5:conj:and|9:nsubj	Entity=4)
9	creates	create	VERB	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	2	acl:relcl	2:acl:relcl	Entity=103)
10-11	doesn't	_	_	_	_	_	_	_	_
10	does	do	AUX	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	12	aux	12:aux	Discourse=same-unit_m:96->94:1
11	n't	not	PART	RB	Polarity=Neg	12	advmod	12:advmod	_
12	last	last	VERB	VB	VerbForm=Inf	0	root	0:root	_
13	long	long	ADV	RB	Degree=Pos	12	advmod	12:advmod	_
14	at	at	ADP	IN	_	15	case	15:case	_
15	all	all	DET	DT	PronType=Tot	12	obl	12:obl:at	_
16	--	-	PUNCT	:	_	19	punct	19:punct	_
17	maybe	maybe	ADV	RB	_	19	advmod	19:advmod	Discourse=elaboration-additional:97->94:2
18	a	a	DET	DT	Definite=Ind|PronType=Art	19	det	19:det	Entity=(104-time-new-cf4-2-sgl
19	couple	couple	NOUN	NN	Number=Sing	12	obl:npmod	12:obl:npmod	_
20	of	of	ADP	IN	_	21	case	21:case	_
21	minutes	minute	NOUN	NNS	Number=Plur	19	nmod	19:nmod:of	Entity=104)|SpaceAfter=No
22	.	.	PUNCT	.	_	12	punct	12:punct	_
